Deck 20: More About Tests

Question 1

A psychologist claims that more than 6.4% of the population suffers from professional problems due to extreme shyness.Identify the Type II error in this context.

A)The error of rejecting the claim that the true proportion is at most 6.4% when it really is at most 6.4%.
B)The error of accepting the claim that the true proportion is more than 6.4% when it really is more than 6.4%.
C)The error of rejecting the claim that the true proportion is more than 6.4% when it really is more than 6.4%.
D)The error of failing to accept the claim that the true proportion is at most 6.4% when it is actually more than 6.4%.
E)The error of failing to reject the claim that the true proportion is at most 6.4% when it is actually more than 6.4%.

Answer 1

The error of failing to reject the claim that the true proportion is at most 6.4% when it is actually more than 6.4%.

Question 2

A weight loss centre provided a loss for 72% of its participants.The centre's leader decides to test a new weight loss strategy to see if it's better and receives a P-value of 0.23.What is reasonable to conclude about the new strategy using α = 0.10?

A)There is a 77% chance of the strategies being equally effective.
B)There is a 23% chance of the strategies being equally effective.
C)If the percentage of participants who lose weight has not changed (not increased),then there is a 23% chance of seeing the increase in the percentage of participants who lose weight that we observed (or higher)from natural sampling variation.At α = 0.10,we reject the null hypothesis and conclude that the new strategy is effective.
D)We can say there is a 23% chance of not seeing the strategies being equally effective in the results we observed from natural sampling variation.We conclude the new strategy is more effective.
E)If the percentage of participants who lose weight has not changed,then there is a 23% chance of seeing the increase in the percentage of participants who lose weight that we observed (or higher)from natural sampling variation.At α = 0.10,we fail to reject the null hypothesis that the percentage has not changed from 72%.There is insufficient evidence to conclude that the new strategy is effective.

Answer 2

If the percentage of participants who lose weight has not changed,then there is a 23% chance of seeing the increase in the percentage of participants who lose weight that we observed (or higher)from natural sampling variation.At α = 0.10,we fail to reject the null hypothesis that the percentage has not changed from 72%.There is insufficient evidence to conclude that the new strategy is effective.

Question 3

A new manager,hired at a large warehouse,was told to reduce the 26% employee sick leave.The manager introduced a new incentive program for employees with perfect attendance.The manager decides to test the new program to see if it's better and receives a P-value of 0.06.What is reasonable to conclude about the new strategy using α = 0.05?

A)We can say there is a 6% chance of seeing the new program having an effect the employee attendance percentage in the results we observed from natural sampling variation.We conclude the new program is more effective.
B)If the sick leave percentage has not changed,then there is only a 6% chance of seeing the decrease in the sick leave percentage we observed (or lower)from natural sampling variation.At α = 0.05,we reject the null hypothesis that the sick leave percentage has not changed and conclude that the new incentive program is effective.
C)There is a 6% chance of the new incentive program having no effect the employee attendance percentage.
D)If the sick leave percentage has not changed,then there is only a 6% chance of seeing the decrease in the sick leave percentage we observed (or lower)from natural sampling variation.At α = 0.05,we fail to reject the null hypothesis that the sick leave percentage has not changed.There is insufficient evidence to conclude that the new incentive program is effective.
E)There is a 94% chance of the new incentive program having no effect on the employee attendance percentage.

Answer 3

If the sick leave percentage has not changed,then there is only a 6% chance of seeing the decrease in the sick leave percentage we observed (or lower)from natural sampling variation.At α = 0.05,we fail to reject the null hypothesis that the sick leave percentage has not changed.There is insufficient evidence to conclude that the new incentive program is effective.

Question 4

A dentist that is developing detection devices to search for tooth decay has concluded that his new device is significantly better than taking X-rays.He made this decision using α = 0.05.Would he have made the same decision at α = 0.10 and α = 0.01?

Question 5

Researchers concerned with the effect of loud music on teenagers' hearing found that there wasn't evidence of a higher hearing loss among teenagers who frequently attended rock concerts.They based this conclusion on a test using α = 0.05.Would they have made the same decision at α = 0.10 and α = 0.01?

Question 6

According to the 2004 Canadian Community Health Survey,23.1% of Canadians aged 18 or older were considered obese;that is,they had a body mass index (BMI)of 30 more higher.Suppose you believe that the percentage of obese Canadians has decreased since 2004 and wish to test your belief.Identify the Type I error in this context.

A)You conclude that obesity is on the rise since it can only increase.
B)You conclude that the percentage of obese Canadians is on the decline,but in fact it has stayed the same or increased.
C)You conclude that the percentage of obese Canadians has increase or decreased,but it definitely has not stayed the same.
D)You conclude that the percentage of obese Canadians has stayed the same or increased,but it has actually decreased.
E)A Type I error is not possible in this situation.

Question 7

The seller of a loaded die claims that it will favour the outcome 6.We don't believe that claim,and roll the die 350 times to test an appropriate hypothesis.Our P-value turns out to be 0.01.Provide an appropriate conclusion using α = 0.05?

A)We can say there is a 1% chance of not seeing a fair die in the results we observed from natural sampling variation.We conclude the die is loaded.
B)If the die does not favour the outcome 6,then there is only a 1% chance of seeing a sample proportion of the outcome 6 as high (or higher)than that which we observed from natural sampling variation.At α = 0.05,we reject the null hypothesis and conclude that the die will favour the outcome 6.
C)If the die does not favour the outcome 6,then there is only a 1% chance of seeing a sample proportion of the outcome 6 as high (or higher)than that which we observed from natural sampling variation.At α = 0.05,we fail to reject the null hypothesis that the die does not favour the outcome 6.That is,there is insufficient evidence to conclude that the die will favour the outcome 6.
D)There is a 1% chance of a fair die.
E)There is a 99% chance of a fair die.

Question 8

A skeptical paranormal researcher claims that the proportion of Americans that have seen a UFO,p,is less than 5%.Identify the Type II error in this context.

A)The error of rejecting the claim that the true proportion is less than 5% when it really is less than 5%.
B)The error of failing to reject the claim that the true proportion is at least 5% when it is actually less than 5%.
C)The error of accepting the claim that the true proportion is at least 5% when it really is at least 5%.
D)The error of rejecting the claim that the true proportion is at least 5% when it really is at least 5%.
E)The error of accepting the claim that the true proportion is at least 5% when it is actually less than 5%.

Question 9

A manager of a large company believes that 95% of her employees use their 40 hours of weekly work time productively.A random survey given to some of the employees found that only 92.7% of her employees used their time productively.A statistician rejected the 95% hypothesis with a P-value of P = 0.021.

Question 10

Farmers concerned with the affect of snowfall levels on their crops found that there wasn't evidence of a decrease in crop growth.They based this conclusion on a test using α = 0.10.Would they have made the same decision at α = 0.05 and α = 0.01?

Question 11

According to the 2004 Canadian Community Health Survey,23.1% of Canadians aged 18 or older were considered obese;that is,they had a body mass index (BMI)of 30 more higher.Suppose you believe that the percentage of obese Canadians has increased since 2004 and wish to test your belief.You hire an independent agency to conduct a hypothesis test and they come up with a P-value of 0.028.What is reasonable to conclude using α = 0.05?

A)There is a 2.8% chance that the percentage of obese Canadians has not changed.
B)If the percentage of obese Canadians has not changed,then there is only a 2.8% chance of seeing the increase in the percentage of obese Canadians that we observed (or higher)from natural sampling variation.At α = 0.05,we fail to reject the null hypothesis that the percentage of obese Canadians has not changed.There is insufficient evidence to conclude that the percentage of obese Canadians is higher than 23.1%.
C)There is a 97.2% chance that the percentage of obese Canadians has not changed.
D)We can say there is a 2.8% chance that the percentage of obese Canadians increase in the results we observed from natural sampling variation.
E)If the percentage of obese Canadians has not changed,then there is only a 2.8% chance of seeing the increase in the percentage of obese Canadians that we observed (or higher)from natural sampling variation.At α = 0.05,we reject the null hypothesis that the percentage of obese Canadians has not changed and conclude that the percentage of obese Canadians is now higher than 23.1%.

Question 12

A university wants to increase its retention rate of 4% for graduating students from the previous year.After implementing several new programs during the last two years,the university reevaluated its retention rate.Identify the Type I error in this context.

A)The university stops all new programs,but in fact retention is on the rise and the programs help.
B)The university concludes that retention is on the rise,but in fact the new programs do not help retention.
C)The product of the university's sample size and sample proportion was less than 10.
D)The university sampled all students at the university.
E)The university concludes that retention is on the rise since the retention rate can only increase.

Question 13

A university wants to increase its retention rate of 4% for graduating students from the previous year.After implementing several new programs during the last two years,the university conducts a hypothesis test to determine if the retention rate has increased and obtains a P-value of 0.075.What is reasonable to conclude about the new programs using α = 0.05?

A)There is a 7.5% chance of the new programs having no effect on the retention rate.
B)We can say there is a 7.5% chance of seeing the new programs having an effect on the retention rate in the results we observed from natural sampling variation.We conclude the new programs are more effective.
C)There is a 92.5% chance of the new programs having no effect on the retention rate.
D)If the new programs have no effect on the retention rate,then there is only a 7.5% chance of seeing the increase in the retention rate that we observed (or higher)from natural sampling variation.At α = 0.05,we reject the null hypothesis that the new programs have no effect on the retention rate and conclude that the programs have been effective in increasing the retention rate.
E)If the new programs have no effect on the retention rate,then there is only a 7.5% chance of seeing the increase in the retention rate that we observed (or higher)from natural sampling variation.At α = 0.05,we fail to reject the null hypothesis that the new programs have no effect on the retention rate.There is insufficient evidence to conclude that the programs have been effective in increasing the retention rate.

Question 14

An entomologist writes an article in a scientific journal which claims that fewer than 3% of male fireflies are unable to produce light due to a genetic mutation.Identify the Type I error in this context.

A)The error of failing to accept the claim that the true proportion is at least 3% when it is actually less than 3%.
B)The error of rejecting the claim that the true proportion is at least 3% when it really is at least 3%.
C)The error of failing to reject the claim that the true proportion is at least 3% when it is actually less than 3%.
D)The error of rejecting the claim that the true proportion is less than 3% when it really is less than 3%.
E)The error of accepting the claim that the true proportion is at least 3% when it really is at least 3%.

Question 15

The mayor's disapproval rating was previously 13%.After a political ad campaign for a city's mayor,pollsters check the disapproval ratings.They test the hypothesis that the ads produced no change against the alternative that the ratings are now below 13%,and find a P-value of 0.11.Provide an appropriate conclusion using α = 0.10?

A)There is an 89% chance the ads produced no change in ratings.
B)If the ads produced no change in the mayor's disapproval rating,then there is an 11% chance of seeing a sample proportion as low (or lower)than that which we observed from natural sampling variation.At α = 0.10,we reject the null hypothesis and conclude that the disapproval rating is below 13%.
C)There is an 11% chance the ads produced no change in ratings.
D)We can say there is an 11% chance of seeing the ads produce a ratings change in the results we observed from natural sampling variation.We conclude the disapproval ratings are lower.
E)If the ads produced no change in the mayor's disapproval rating,then there is an 11% chance of seeing a sample proportion as low (or lower)than that which we observed from natural sampling variation.At α = 0.10,we fail to reject the null hypothesis that the disapproval rating is 13%.There is insufficient evidence to conclude that the disapproval rating is below 13%.

Question 16

A researcher has tested the difference between the means of a treatment group and a placebo group.With a P-value of 0.034,he concludes there is a difference.

Question 17

A weight loss centre provided a loss for 72% of its participants.The centre's leader decides to test a new weight loss strategy.Identify the Type I error in this context.

A)The centre sampled all participants at the weight loss centre.
B)The centre concludes that the proportion of participants losing weight is increasing,but in fact the new strategy does not help weight loss.
C)The product of the centre's sample size and sample proportion was less than 10.
D)The centre concludes that proportion of weight loss is increasing since the weight loss level can only increase.
E)The centre stops the new strategy,but in fact weight loss is increasing and the strategy helps.

Question 18

A diesel engine company that is developing a new engine has concluded that the updated engine provides better fuel economy than the current engine.They made this decision using α = 0.01.Would they have made the same decision at α = 0.10 and α = 0.05?

Question 19

A new math program may reduce the number of elementary students who perform below their grade level.The company that developed this program supplied materials and teacher training to 3000 children and 400 teachers.Statistical analysis of the results showed that the percentage of students who did not attain the grade level standard was reduced from 24.3% to 18.5%.The hypothesis that the new reading program did not produce improvement was rejected with a P-value of 0.047.

Question 20

Have harsher laws decreased the number of drivers under the influence? Observations of Friday and Saturday evening traffic failed to find evidence of a significant change compared with ten years ago.The P-value of the study was P = 0.23.

Question 21

A skeptical paranormal researcher claims that the proportion of Americans that have seen a UFO is less than 4%.What are the null and alternative hypotheses?

A)
B)
C)
D)
E)

Question 22

In April of 2011,the unemployment rate in Canada was reported to be 7.6%.Suppose that Statistics Canada claims that the current unemployment rate is lower than that of April 2011.Suppose you wish to conduct a test to determine if the current unemployment rate is lower than that of April 2011.Identify the Type II error in this context.

A)You conclude that the unemployment rate has increased.
B)You conclude that there in no change in unemployment,but in fact the unemployment rate is decreasing.
C)You conclude that unemployment is declining since the unemployment rate can only decrease.
D)You conclude that unemployment is on the decline,but in fact there is no change in unemployment.
E)A Type II error is not possible in this situation.

Question 23

According to the 2004 Canadian Community Health Survey,23.1% of Canadians aged 18 or older were considered obese;that is,they had a body mass index (BMI)of 30 more higher.Suppose you believe that the percentage of obese Canadians has increased since 2004.To test your belief take a random sample of 1000 Canadians.If you plan to perform the test at α = 0.01 and the true percentage of obese Canadians is currently 24.8%,what is the power of the test?

A)0.9801
B)0.8485
C)0.7521
D)0.6046
E)0.1515

Question 24

In April of 2011,the unemployment rate in Canada was reported to be 7.6%.Suppose that Statistics Canada claims that the current unemployment rate is lower than that of April 2011.To test their belief,they plan to take a random sample size of 1000 people.If they plan to perform the test at α = 0.05 and the unemployment rate is currently 6.1%,what is the power of the test?

A)0.8547
B)0.0104
C)0.5636
D)0.9896
E)0.4364

Question 25

Consider a hypothesis test where the probability of a Type I error is 0.10 and the probability of a Type II error is 0.08.What is the power of the test?

A)0.008
B)0.90
C)0.10
D)0.92
E)0.08

Question 26

An entomologist writes an article in a scientific journal which claims that fewer than 29% of male fireflies are unable to produce light due to a genetic mutation.What are the null and alternative hypotheses?

A)
B)
C)
D)
E)

Question 27

In April of 2011,the unemployment rate in Canada was reported to be 7.6%.Suppose that Statistics Canada claims that the current unemployment rate is lower than that of April 2011.To test their belief,they plan to take a random sample size of 1000 people.If they plan to perform the test at α = 0.01 and the unemployment rate is currently 6.1%,what is the power of the test?

A)0.1326
B)0.8674
C)0.7224
D)0.9215
E)0.2776

Question 28

Health Canada reports that,in 2005,85% of Canadians were satisfied with the health care services they received.Suppose you wish to conduct a hypothesis test to determine if there is now a smaller percentage of Canadians are satisfied with the health care services they received.Identify the Type I error in this context.

A)You take a sample more than 10% of the population size.
B)A Type I error is not possible in this situation.
C)You fail to conclude that the percentage of satisfied Canadians has decreased,but it actually has decreased.
D)You conclude that the percentage of satisfied Canadians has decreased,but it has actually stayed the same (or increased).
E)You conclude that the percentage of satisfied Canadians has increased.

Question 29

A city claims that 75% of all low income housing is 1500 sq.ft.The tenants believe the proportion of housing this size is smaller than the claim,and hire an independent firm to test the hypothesis.Identify the Type I error in this context.

A)The firm concludes that the proportion of housing less than 1500 sq.ft.is smaller,but in fact there is no change in the proportion.
B)The product of the firm's sample size and sample proportion was less than 10.
C)The firm sampled all low income houses.
D)The firm concludes that the proportion of housing this size is rising since the majority of housing can only increase.
E)The firm shows there in no change in the proportion of housing this size,but in fact the proportion of houses less than 1500 sq.ft.is smaller.

Question 30

According to the 2004 Canadian Community Health Survey,23.1% of Canadians aged 18 or older were considered obese;that is,they had a body mass index (BMI)of 30 more higher.Suppose you believe that the percentage of obese Canadians has increased since 2004.To test your belief take a random sample of 1000 Canadians.If you plan to perform the test at α = 0.10 and the true percentage of obese Canadians is currently 25.9%,what is the power of the test?

A)0.7411
B)0.6046
C)0.2148
D)0.3954
E)0.7852

Question 31

Five years ago,a company found that 8% of its employees commuted to work by car.A survey investigates whether the current proportion of employees who commute by car to work is higher than it was five years ago.What are the null and alternative hypotheses?

A)
B)
C)
D)
E)

Question 32

According to the 2004 Canadian Community Health Survey,23.1% of Canadians aged 18 or older were considered obese;that is,they had a body mass index (BMI)of 30 more higher.Suppose you believe that the percentage of obese Canadians has increased since 2004.To test your belief take a random sample of 1000 Canadians.If you plan to perform the test at α = 0.05 and the true percentage of obese Canadians is currently 24.8%,what is the power of the test?

A)0.6046
B)0.0171
C)0.752
D)0.3954
E)0.769

Question 33

A new manager,hired at a large warehouse,was told to reduce the 26% employee sick leave.The manager introduced a new incentive program for employees with perfect attendance.The manager decides to test the new program to see if it's better.What are the null and alternative hypotheses?

A)
B)
C)
D)
E)

Question 34

In April of 2011,the unemployment rate in Canada was reported to be 7.6%.Suppose that Statistics Canada wishes to determine if the current unemployment rate differs from that of April 2011.To perform a hypothesis test,they plan to take a random sample size of 1000 people.If they plan to perform the test at α = 0.05 and the unemployment rate is currently 8.1%,what is the power of the test?

A)0.9500
B)0.0066
C)0.0934
D)0.1000
E)0.0500

Question 35

Five years ago,a company found that 8% of its employees commuted to work by car.A survey investigates whether the current proportion of employees who commute by car to work is higher than it was five years ago.Identify the Type II error in this context.

A)The survey states there in no change in commuting,but in fact commuting by car is increasing.
B)You conclude that commuting by car is on the decline.
C)The survey concludes that commuting by car is on the rise,but in fact there is no change in commuting.
D)The survey concludes that commuting by car is on the rise since the commuting can only increase.
E)A Type II error is not possible in this situation.

Question 36

In April of 2011,the unemployment rate in Canada was reported to be 7.6%.Suppose that Statistics Canada claims that the current unemployment rate is lower than that of April 2011.To test their belief,they plan to take a random sample size of 1000 people.If they plan to perform the test at α = 0.10 and the unemployment rate is currently 6.1%,what is the power of the test?

A)0.8674
B)0.2877
C)0.9215
D)0.7123
E)0.1326

Question 37

A weight loss centre provided a loss for 72% of its participants.The centre's leader decides to test a new weight loss strategy to see if it's better.What are the null and alternative hypotheses?

A)
B)
C)
D)
E)

Question 38

According to the 2004 Canadian Community Health Survey,23.1% of Canadians aged 18 or older were considered obese;that is,they had a body mass index (BMI)of 30 more higher.Suppose you believe that the percentage of obese Canadians has increased since 2004.To test your belief take a random sample of 1000 Canadians.If you plan to perform the test at α = 0.05 and the true percentage of obese Canadians is currently 25.9%,what is the power of the test?

A)0.67
B)0.05
C)0.33
D)0.95
E)0.74

Question 39

According to the 2004 Canadian Community Health Survey,23.1% of Canadians aged 18 or older were considered obese;that is,they had a body mass index (BMI)of 30 more higher.Suppose you believe that the percentage of obese Canadians has increased since 2004 and wish to test your belief.What are the null and alternative hypotheses?

A)
B)
C)
D)
E)

Question 40

In April of 2011,the unemployment rate in Canada was reported to be 7.6%.Suppose that Statistics Canada claims that the current unemployment rate is lower than that of April 2011.To test their belief,they plan to take a random sample size of 1000 people.If they plan to perform the test at α = 0.05 and the unemployment rate is currently 7.1%,what is the power of the test?

A)0.1401
B)0.1326
C)0.8674
D)0.9215
E)0.8599

Question 41

A company is willing to renew its publishing contract with a popular statistics book author only if he can prove that his book can sell to more than 22% of the entire statistics market.The publishing company contacts 5000 statistics professors at random and only 1050 professors were interested in the book.Should the company renew the contract? Should the company renew the contract? State the critical value required to perform an appropriate hypothesis test using α = 0.01.

A)2.576
B)3.09
C)2.326
D)1.645
E)1.96

Question 42

A city claims that 75% of all low income housing is 1500 sq.ft.The tenants believe the proportion of housing this size is smaller than the claim,and hire an independent firm to test a random sample size of 120 and found 1500 sq.ft.housing at 66%.State the critical value required to perform an appropriate hypothesis test using α = 0.001.

A)2.326
B)-2.326
C)-3.29
D)3.09
E)-3.09

Question 43

Five years ago,a company found that 8% of its employees commuted to work by car.A survey investigates whether the current proportion of employees who commute by car to work is higher than it was five years ago.A test on employee commuting by car was done on a random sample of 1000 employees,and found car commuting to be 12%.Test an appropriate hypothesis using α = 0.05 and state your conclusion.Be sure the appropriate assumptions and conditions are satisfied before you proceed.

Question 44

A Science professor has observed over several years that about 15% of the students who initially major in Science drop out of the program after their freshman year.The department head suggested making the curriculum easier by taking a couple of 300 level courses out of the requirements.With the new curriculum in tact,590 began their freshman year as Science majors and only 52 dropped out of the program.Should the college continue with the easier curriculum? State the critical value required to perform an appropriate hypothesis test using α = 0.01.

A)-1.645
B)-2.326
C)1.96
D)-1.96
E)1.645

Question 45

A company is willing to renew its publishing contract with a popular calculus book author only if he can prove that his book can sell to more than 15% of the entire calculus market.The publishing company contacts 3000 calculus professors at random and only 420 professors were interested in the book.Should the company renew the contract? State the critical value required to perform an appropriate hypothesis test using α = 0.05.

A)-1.645
B)-2.326
C)1.645
D)1.96
E)-1.96

Question 46

According to the 2004 Canadian Community Health Survey,23.1% of Canadians aged 18 or older were considered obese;that is,they had a body mass index (BMI)of 30 more higher.Suppose you believe that the percentage of obese Canadians has increased since 2004 and wish to test your belief.A current survey of 1000 random Canadians found that 245 were obese.Test an appropriate hypothesis using α = 0.10 and state your conclusion.Be sure the appropriate assumptions and conditions are satisfied before you proceed.

Question 47

A city claims that 75% of all low income housing is 1500 sq.ft.The tenants believe the proportion of housing this size is smaller than the claim,and hire an independent firm to test an appropriate hypothesis.What are the null and alternative hypotheses?

A)
B)
C)
D)
E)

Question 48

A Math professor has observed over several years that about 38% of the students who initially major in Math drop out of the program after their freshman year.The department head suggested making the curriculum easier by taking a couple of 300 level courses out of the requirements.With the new curriculum intact,207 began their freshman year as Math majors and only 59 dropped out of the program.Should the college continue with the easier curriculum? State the critical value required to perform an appropriate hypothesis test using α = 0.05.

A)1.96
B)-1.96
C)-1.645
D)-1.282
E)-1.645 .

Question 49

Five years ago,a company found that 8% of its employees commuted to work by car.A survey investigates whether the current proportion of employees who commute by car to work is higher than it was five years ago.A test on employee commuting by car was done on a random sample of 1000 employees,and found car commuting to be 12%.State the critical value required to perform an appropriate hypothesis test using α = 0.001.

A)1.96
B)2.326
C)3.09
D)3.29
E)2.576

Question 50

The management of a water park has concerns about the chlorine level of 0.4% mg/mL increasing to an unsafe level.The management tests the hypothesis that the park's chlorine proportions have remained the same,hat are the null and alternative hypotheses?

A)
B)
C)
D)
E)

Question 51

In April of 2011,the unemployment rate in Canada was reported to be 7.6%.Suppose you wish to conduct a test to determine if the current unemployment rate differs from that of April 2011.What are the null and alternative hypotheses?

A)
B)
C)
D)
E)

Question 52

In April of 2011,the unemployment rate in Canada was reported to be 7.6%.You wish to know if the current unemployment rate differs from that of April 2011.You take a random sample size of 1000 and found unemployment at 6.1%.State the critical value required to perform an appropriate hypothesis test using α = 0.05.

A)1.282
B)1.96
C)2.576
D)1.645
E)3.09

Question 53

According to the 2004 Canadian Community Health Survey,23.1% of Canadians aged 18 or older were considered obese;that is,they had a body mass index (BMI)of 30 more higher.Suppose you believe that the percentage of obese Canadians has decreased since 2004 and wish to test your belief.A current survey of 1000 random Canadians found that 219 were obese.State the critical value required to perform an appropriate hypothesis test using α = 0.05.

A)-1.645
B)-1.96
C)1.96
D)1.282
E)1.645

Question 54

A weight loss centre provided a loss for 72% of its participants.The centre's leader decides to test a new weight loss strategy on a random sample size of 140 and found weight loss in 78% of the participants.State the critical value required to perform an appropriate hypothesis test using α = 0.01.

A)-1.645
B)1.96
C)2.576
D)2.326
E)1.645

Question 55

A city claims that 75% of all low income housing is 1500 sq.ft.The tenants believe the proportion of housing this size is smaller than the claim,and hire an independent firm to test a random sample size of 120 and found 1500 sq.ft.housing at 66%.Test an appropriate hypothesis using α = 0.01 and state your conclusion.Be sure the appropriate assumptions and conditions are satisfied before you proceed.

Question 56

In April of 2011,the unemployment rate in Canada was reported to be 7.6%.Suppose that Statistics Canada claims that the current unemployment rate is lower than that of April 2011.Suppose a test was conducted on current unemployment and a random sample size of 1000 and found unemployment at 6.1%.Test an appropriate hypothesis using α = 0.05 and state your conclusion.Be sure the appropriate assumptions and conditions are satisfied before you proceed.

Question 57

A weight loss centre provided a loss for 72% of its participants.The centre's leader decides to test a new weight loss strategy on a random sample size of 140 and found weight loss in 78% of the participants.Test an appropriate hypothesis using α = 0.05 and state your conclusion.Be sure the appropriate assumptions and conditions are satisfied before you proceed.

Question 58

A university wants to increase its retention rate of 4% for graduating students from the previous year.After implementing several new programs during the last two years,the university reevaluated its retention rate using a random sample of 352 students and retained 18 students.Should the university continue its new programs? Test an appropriate hypothesis using α = 0.10 and state your conclusion.Be sure the appropriate assumptions and conditions are satisfied before you proceed.

Question 59

A university wants to increase its retention rate of 4% for graduating students from the previous year.After implementing several new programs during the last two years,the university reevaluated its retention rate using a random sample of 352 students and retained 18 students.Should the university continue its new programs? State the critical value required to perform an appropriate hypothesis test using α = 0.10.

A)1.645
B)2.576
C)3.09
D)1.282
E)1.96

Question 60

A mayor is concerned about the percentage of city residents who express disapproval of his job performance.His political committee pays for a newspaper ad,hoping that it will keep the disapproval rate below 22%.They will use a follow-up poll to assess the ad's effectiveness.

A)
B)
C)
D)
E)

Question 61

A company has surveyed a sample of its employees to find out how many might take advantage of a weight loss program.The table below shows the results.For which of the groups could we use our methods of inference to determine a 95% confidence interval for the proportion of employees who would be willing to participate in the program?

Question 62

A Science professor has observed over several years that about 15% of the students who initially major in Science drop out of the program after their freshman year.The department head suggested making the curriculum easier by taking a couple of 300 level courses out of the requirements.With the new curriculum in tact,590 began their freshman year as Science majors and only 52 dropped out of the program.Should the college continue with the easier curriculum? Test an appropriate hypothesis using α = 0.05 and state your conclusion.Be sure the appropriate assumptions and conditions are satisfied before you proceed.

Question 63

A company has surveyed a sample of its employees to find out how many might take advantage of a weight loss program.The table below shows the results.Give the 95% confidence interval for the group(s)for which we could use our methods of inference for the proportion of employees who would be willing to participate in the program.

Question 64

A professional basketball player with a poor free throw percentage gets a personal coach to help him increase his percentage.He tells his coach that he has raised his proficiency from 40% to 60%.To see whether the athlete has improved,the coach asks the athlete to take ten shots.He hits 7 out of 10.If the player really can hit 60% now,and it takes at least 7 out of 10 successful shots to convince the coach,what's the power of the test?

Question 65

A professional basketball player with a poor free throw percentage gets a personal coach to help him increase his percentage.He tells his coach that he has raised his proficiency from 70% to 90%.To see whether the athlete has improved,the coach asks the athlete to take 10 shots.He hits 10 out of 10.Suppose the athlete really is no better than before (still a 70% shooter).What's the probability that he could hit at least 10 out of 10 shots anyway?

Question 66

A Math professor has observed over several years that about 38% of the students who initially major in Math drop out of the program after their freshman year.The department head suggested making the curriculum easier by taking a couple of 300 level courses out of the requirements.With the new curriculum intact,207 began their freshman year as Math majors and only 59 dropped out of the program.Should the college continue with the easier curriculum? Test an appropriate hypothesis using α = 0.05 and state your conclusion.Be sure the appropriate assumptions and conditions are satisfied before you proceed.

Question 67

A company is willing to renew its publishing contract with a popular calculus book author only if he can prove that his book can sell to more than 15% of the entire calculus market.The publishing company contacts 3000 calculus professors at random and only 420 professors were interested in the book.Should the company renew the contract? Test an appropriate hypothesis using α = 0.05 and state your conclusion.Be sure the appropriate assumptions and conditions are satisfied before you proceed.

Question 68

A company is willing to renew its publishing contract with a popular statistics book author only if he can prove that his book can sell to more than 22% of the entire statistics market.The publishing company contacts 5000 statistics professors at random and only 1050 professors were interested in the book.Should the company renew the contract? Test an appropriate hypothesis using α = 0.01 and state your conclusion.Be sure the appropriate assumptions and conditions are satisfied before you proceed.

Question 69

A company has surveyed a sample of its employees to find out how many might take advantage of a weight loss program.The table below shows the results.Give the 95% confidence interval for Building A for the proportion of employees who would be willing to participate in the program.Based on this interval,can we say that the proportion differs from 11%? At which level of significance are you making this decision?