Question 1

Using the z table, find the critical value (or values) for an   = 0.12 right-tailed test.

Accepted Answer

A)  0.59 
B)  0.78 
C)  1.18 
D)  1.56 
A)  0.59 
B)  0.78 
C)  1.18 
D)  1.56 C

Question 2

A machine fills 12-ounce bottles with soda. For the machine to function properly, the standard deviation of the sample must be less than or equal to 0.02 ounce. A sample of 8 bottles is selected, and the number of ounces of soda in each bottle is given. At   , can you reject the claim that the machine is functioning properly? Justify your answer. (Assume that the variables are approximately normally distributed.)

Accepted Answer

A)    ,   ; There is evidence to reject the claim that the machine is working properly. 
B)    ,   ; There is evidence to reject the claim that the machine is working properly. 
C)    ,   ; There is not enough evidence to reject the claim that the machine is working properly. 
D)    ,   ; There is evidence to reject the claim that the machine is working properly. 
A)    ,   ; There is evidence to reject the claim that the machine is working properly. 
B)    ,   ; There is evidence to reject the claim that the machine is working properly. 
C)    ,   ; There is not enough evidence to reject the claim that the machine is working properly. 
D)    ,   ; There is evidence to reject the claim that the machine is working properly. D

Question 3

The numerical value obtained from a statistical test is called the _______________.

Accepted Answer

test value

Question 4

In performing a hypothesis test, one should decide whether to reject or not reject the null hypothesis before summarizing the results.

Accepted Answer

A) True 
 B)False

Question 5

What is the critical value for a right-tailed t test when α = 0.025 and n = 13?

Accepted Answer

A)  2.179 
B)  0.697 
C)  0.695 
D)  2.201 
A)  2.179 
B)  0.697 
C)  0.695 
D)  2.201

Question 6

Assume that a 99% confidence interval for the mean is   . The null hypothesis   at   0.01 would

Accepted Answer

A)  not be rejected because 11.0 is less than 15.0. 
B)  not be rejected because 11.0 is between 9.0 and 15.0. 
C)  be rejected because 11.0 is more than 9.0. 
D)  be rejected because 11.0 is not equal to 12.00. 
A)  not be rejected because 11.0 is less than 15.0. 
B)  not be rejected because 11.0 is between 9.0 and 15.0. 
C)  be rejected because 11.0 is more than 9.0. 
D)  be rejected because 11.0 is not equal to 12.00.

Question 7

Stating the hypothesis should be the first step used in hypothesis testing.

Accepted Answer

A) True 
 B)False

Question 8

At a certain university, the average attendance at basketball games has been 3225. Due to the dismal showing of the team this year, the attendance for the first 12 games has averaged only 2865 with a standard deviation of 735. The athletic director claims that the attendance is the same as last year. What is the test value needed to evaluate the claim?

Accepted Answer

A)  -1.70 
B)  -3.79 
C)  -4.48 
D)  -5.88 
A)  -1.70 
B)  -3.79 
C)  -4.48 
D)  -5.88

Question 9

Using the z table, find the critical value (or values) for an   = 0.021 left-tailed test.

Accepted Answer

A)  -2.03 
B)  -2.31 
C)  -1.01 
D)  -1.15 
A)  -2.03 
B)  -2.31 
C)  -1.01 
D)  -1.15

Question 10

A political strategist claims that 56% of voters in Madison County support his candidate. In a poll of 200 randomly selected voters, 100 of them support the strategist's candidate. At   = .05, is the political strategist's claim warranted?

Accepted Answer

A)  No, because the test value -1.01 is in the noncritical region. 
B)  No, because the test value -2.22 is in the critical region. 
C)  Yes, because the test value -2.22 is in the noncritical region. 
D)  Yes, because the test value -1.71 is in the noncritical region. 
A)  No, because the test value -1.01 is in the noncritical region. 
B)  No, because the test value -2.22 is in the critical region. 
C)  Yes, because the test value -2.22 is in the noncritical region. 
D)  Yes, because the test value -1.71 is in the noncritical region.

Question 11

Which type of null hypothesis is used in the figure below?

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 12

The average magnesium concentration in ground water around Metro City is   parts per million (ppm) with a standard deviation of   . The table below shows the ground-water magnesium concentrations (ppm) from random sites in a suburb located 15 miles away. At   , can it be concluded that the average magnesium concentration in the suburb differs from 86.2 ppm?   a. State the hypotheses and identify the claim.
b. Find the critical values.
c. Compute the test statistic.
d. Make a decision.
e. Summarize the results.

Accepted Answer

a. @#IMG-DLM& b. @#IMG-DLM& c. z = -4.6 ( @#IMG-DLM& )
d. Re

Question 13

If the probability of a type II error in a hypothesis test is 0.25, and   0.05, then the power of this test is

Accepted Answer

A)  0.05 
B)  0.25 
C)  0.75 
D)  0.95 
A)  0.05 
B)  0.25 
C)  0.75 
D)  0.95

Question 14

Using the z table, determine the critical values for a two-tailed test when α = 0.03.

Accepted Answer

A)  ± 1.88 
B)  ± 2.17 
C)  ± 0.18 
D)  ± 0.06 
A)  ± 1.88 
B)  ± 2.17 
C)  ± 0.18 
D)  ± 0.06

Question 15

Doctors nationally believe that 74% of a certain type of operation are successful. In a particular hospital, 57 of these operations were observed and 47 of them were successful. At   = .05, is this hospital's success rate different from the national average?

Accepted Answer

A)  No, because the test value 0.86 is in the noncritical region. 
B)  Yes, because the test value 0.86 is in the critical region. 
C)  No, because the test value 1.46 is in the noncritical region. 
D)  Yes, because the test value 1.46 is in the noncritical region. 
A)  No, because the test value 0.86 is in the noncritical region. 
B)  Yes, because the test value 0.86 is in the critical region. 
C)  No, because the test value 1.46 is in the noncritical region. 
D)  Yes, because the test value 1.46 is in the noncritical region.

Question 16

A type I error is only a possibility when the null hypothesis is not rejected.

Accepted Answer

A) True 
 B)False

Question 17

The probability of committing a type II error is denoted as β.

Accepted Answer

A) True 
 B)False

Question 18

Find the P-value for the test value.
T = 1.581, n = 23, right-tailed

Accepted Answer

A)  0.0321 
B)  0.1282 
C)  0.0641 
D)  0.0687 
A)  0.0321 
B)  0.1282 
C)  0.0641 
D)  0.0687

Question 19

Dr. Christina Cuttleman, a nutritionist, claims that the average number of calories in a serving of popcorn is 75 with a standard deviation of 7. A sample of 50 servings of popcorn was found to have an average of 78 calories. Check Dr. Cuttleman's claim at α = 0.05.

Accepted Answer

@#IMG-DLM& (the claim) and @#IMG-DLM& Critical values: ±1.96

Question 20

Science fiction novels average 250 pages in length. The average length of 10 randomly chosen novels written by I. M. Wordy was 295 pages in length with a standard deviation of 60. At   = .05, are Wordy's novels significantly longer than the average science fiction novel?

Accepted Answer

@#IMG-DLM& Critical value: 1.833
Test value: 2.372

Using the z table, find the critical value (or values) for an = 0.12 right-tailed test.

The numerical value obtained from a statistical test is called the _______________.

In performing a hypothesis test, one should decide whether to reject or not reject the null hypothesis before summarizing the results.

What is the critical value for a right-tailed t test when α = 0.025 and n = 13?

Assume that a 99% confidence interval for the mean is . The null hypothesis at 0.01 would

Stating the hypothesis should be the first step used in hypothesis testing.

Using the z table, find the critical value (or values) for an = 0.021 left-tailed test.

A political strategist claims that 56% of voters in Madison County support his candidate. In a poll of 200 randomly selected voters, 100 of them support the strategist's candidate. At = .05, is the political strategist's claim warranted?

Which type of null hypothesis is used in the figure below?

If the probability of a type II error in a hypothesis test is 0.25, and 0.05, then the power of this test is

Using the z table, determine the critical values for a two-tailed test when α = 0.03.

Doctors nationally believe that 74% of a certain type of operation are successful. In a particular hospital, 57 of these operations were observed and 47 of them were successful. At = .05, is this hospital's success rate different from the national average?

A type I error is only a possibility when the null hypothesis is not rejected.

The probability of committing a type II error is denoted as β.

Find the P-value for the test value. T = 1.581, n = 23, right-tailed

Dr. Christina Cuttleman, a nutritionist, claims that the average number of calories in a serving of popcorn is 75 with a standard deviation of 7. A sample of 50 servings of popcorn was found to have an average of 78 calories. Check Dr. Cuttleman's claim at α = 0.05.

Science fiction novels average 250 pages in length. The average length of 10 randomly chosen novels written by I. M. Wordy was 295 pages in length with a standard deviation of 60. At = .05, are Wordy's novels significantly longer than the average science fiction novel?

The Nature of Probability and Statistics

Frequency Distributions and Graphs

Data Description

Probability and Counting Rules

Discrete Probability Distributions

The Normal Distribution

Confidence Intervals and Sample Size

Testing the Difference Between Two Means, Two Variances, and Two Proportions

Correlation and Regression

Other Chi-Square Tests

Analysis of Variance

Nonparametric Statistics

Sampling and Simulation

Filters

Exam 8: Hypothesis Testing

Using the z table, find the critical value (or values) for an = 0.12 right-tailed test.

The numerical value obtained from a statistical test is called the _______________.

In performing a hypothesis test, one should decide whether to reject or not reject the null hypothesis before summarizing the results.

What is the critical value for a right-tailed t test when α = 0.025 and n = 13?

Assume that a 99% confidence interval for the mean is . The null hypothesis at 0.01 would

Stating the hypothesis should be the first step used in hypothesis testing.

Using the z table, find the critical value (or values) for an = 0.021 left-tailed test.

A political strategist claims that 56% of voters in Madison County support his candidate. In a poll of 200 randomly selected voters, 100 of them support the strategist's candidate. At = .05, is the political strategist's claim warranted?

Which type of null hypothesis is used in the figure below?

If the probability of a type II error in a hypothesis test is 0.25, and 0.05, then the power of this test is

Using the z table, determine the critical values for a two-tailed test when α = 0.03.

Doctors nationally believe that 74% of a certain type of operation are successful. In a particular hospital, 57 of these operations were observed and 47 of them were successful. At = .05, is this hospital's success rate different from the national average?

A type I error is only a possibility when the null hypothesis is not rejected.

The probability of committing a type II error is denoted as β.

Find the P-value for the test value. T = 1.581, n = 23, right-tailed

Dr. Christina Cuttleman, a nutritionist, claims that the average number of calories in a serving of popcorn is 75 with a standard deviation of 7. A sample of 50 servings of popcorn was found to have an average of 78 calories. Check Dr. Cuttleman's claim at α = 0.05.

Science fiction novels average 250 pages in length. The average length of 10 randomly chosen novels written by I. M. Wordy was 295 pages in length with a standard deviation of 60. At = .05, are Wordy's novels significantly longer than the average science fiction novel?

The Nature of Probability and Statistics

Frequency Distributions and Graphs

Data Description

Probability and Counting Rules

Discrete Probability Distributions

The Normal Distribution

Confidence Intervals and Sample Size

Testing the Difference Between Two Means, Two Variances, and Two Proportions

Correlation and Regression

Other Chi-Square Tests

Analysis of Variance

Nonparametric Statistics

Sampling and Simulation

Filters