Question 1

When determining the sample size needed for a proportion for a given level of confidence and sampling error, the closer to 0.50 that p is estimated to be:

Accepted Answer

A)  the smaller the sample size required. 
B)  the larger the sample size required. 
C)  the sample size is not affected. 
D)  the effect cannot be determined from the information given. 
A)  the smaller the sample size required. 
B)  the larger the sample size required. 
C)  the sample size is not affected. 
D)  the effect cannot be determined from the information given. B

Question 2

The test statistic used to test hypotheses about the population variance is given by   = (n- 1)s2 / $\sigma$2, which is chi-squared distributed with n - 1 degrees of freedom when the population random variable is normally distributed with variance equal to $\sigma$2.

Accepted Answer

A) True 
 B)False  True

Question 3

Sinus Drug
A company claims that 10% of the users of a certain sinus drug experience drowsiness.In clinical studies of this sinus drug, 81 of the 900 subjects experienced drowsiness
-{Sinus Drug Narrative} Explain how to use this confidence interval to test the hypotheses.

Accepted Answer

Since the hypothesized value p₀ = 0.10 is included in this 95% confidence interval, we fail to reject H₀ at $\alpha$= 0.05.

Question 4

Researchers determined that 60 Puffs tissues is the average number of tissues used during a cold.Suppose a random sample of 100 Puffs users yielded the following data on the number of tissues used during a cold:   = 52 and s = 22.Suppose the alternative we wanted to test was H1: $\mu$ < 60.The correct rejection region for $\alpha$ = 0.05 is:

Accepted Answer

A) reject H0 if t > 1.6604. B) reject H0 if t 0 if t > 1.9842 or Z 0 if t < -1.9842. A) reject H0 if t > 1.6604. B) reject H0 if t 0 if t > 1.9842 or Z 0 if t < -1.9842.

Question 5

Employees in a large company are entitled to 15-minute water breaks.A random sample of the duration of water breaks for 10 employees was taken with the times shown as: 12, 16, 14, 18, 21, 17, 19, 15, 18, and 16.Assuming that the times are normally distributed, is there enough evidence at the 5% significance level to indicate that on average employees are taking longer water breaks than they are entitled to?

Accepted Answer

H₀: @#LAT-DLM& = 15, H₁:@#LAT-DLM& > 15 Rejection region: t >

Question 6

After calculating the sample size needed to estimate a population proportion to within 0.04, your statistics professor told you the maximum allowable error must be reduced to just .01.If the original calculation led to a sample size of 800, the sample size will now have to be:

Accepted Answer

A)  800 
B)  3,200 
C)  6,400 
D)  12,800 
A)  800 
B)  3,200 
C)  6,400 
D)  12,800

Question 7

The sales manager of a large multinational corporation is concerned that some salespersons perform very well and others quite poorly.To help analyze the problem he draws a random sample of 20 salespersons, determines their commission incomes (in thousands of dollars), and calculates the following statistics:   = $37.2, and s = $7.8.Do these statistics provide sufficient evidence at the 5% significance level to conclude that the population variance exceeds $35 million2?

Accepted Answer

H₀: @#LAT-DLM&² = 35, H₁: @#LAT-DLM&² > 35 Rejection region: @#IMG-DLM& Te

Question 8

Socialist Party Voters
A pollster in Italy wants to challenge a claim that 5% of the registered voters in his country are Socialists; he thinks the percentage is lower than that.In a test of hypothesis, HS1U1B10S1U1B0: p = 0.05 vs.HS1U1B11S1U1B0: p < 0.05, his random sample of size 1,000 registered voters revealed that the number of Socialists was 40.
-{Socialist Voters Narrative} Compute the p-value and explain how to use it to test the hypotheses.

Accepted Answer

p-value = 0.0735.
Si

Question 9

Which of the following statements is false?

Accepted Answer

A)  Because there is one single way to segment a market, managers must consider several variable or characteristics that could be used to identify segments. 
B)  Surveys of customers are used to gather data about various aspects of the market. 
C)  Statistical techniques are applied to the survey data to define the market segments. 
D)  Market segmentation separates consumers of a product into different groups in such a way that members of each group are similar to each other and there are differences between groups. 
A)  Because there is one single way to segment a market, managers must consider several variable or characteristics that could be used to identify segments. 
B)  Surveys of customers are used to gather data about various aspects of the market. 
C)  Statistical techniques are applied to the survey data to define the market segments. 
D)  Market segmentation separates consumers of a product into different groups in such a way that members of each group are similar to each other and there are differences between groups.

Question 10

The test statistic used to test hypotheses about the population variance has a chi-squared distribution with ____________________ degrees of freedom.

Accepted Answer

The answer of The test statistic used to test hypotheses...

Question 11

Market segmentation separates consumers of a product into different groups in such a way that members of each group are similar to each other and there are differences between groups.

Accepted Answer

A) True 
 B)False

Question 12

Which of the following would be an appropriate alternative hypothesis?

Accepted Answer

A)  The population proportion is less than 0.65. 
B)  The sample proportion is less than 0.65. 
C)  The population proportion is equal to 0.65. 
D)  The sample proportion is equal to 0.65. 
A)  The population proportion is less than 0.65. 
B)  The sample proportion is less than 0.65. 
C)  The population proportion is equal to 0.65. 
D)  The sample proportion is equal to 0.65.

Question 13

The area to the right of a certain critical value on a chi-squared distribution is 0.025.For 5 degrees of freedom, the critical value is 11.143.

Accepted Answer

A) True 
 B)False

Question 14

Physicians
A random sample of 200 physicians shows that there are 36 of them who make at least $400,000 a year.
-{Physicians Narrative} Compute the p-value and explain how to use it to test the hypotheses.

Accepted Answer

p-value = 0.0233.
Si

Question 15

A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches.To test this claim against the alternative that the actual proportion of doctors who recommend aspirin is less than 0.90, a random sample of 100 doctors' results in 83 who indicate that they recommend aspirin.The value of the test statistic in this problem is approximately equal to:

Accepted Answer

A) -1.67 
B)  -2.33 
C)  -1.86 
D) -0.14 
A) -1.67 
B)  -2.33 
C)  -1.86 
D) -0.14

Question 16

Based on sample data, the 90% confidence interval limits for the population mean are LCL = 170.86 and UCL = 195.42.If the 10% level of significance were used in testing the hypotheses H0: $\mu$ = 201 vs.H1: $\mu$$\neq$201, the null hypothesis:

Accepted Answer

A)  would be rejected. 
B)  would be accepted. 
C)  would fail to be rejected. 
D)  would become H0: $\mu$ $\neq$ 201 
A)  would be rejected. 
B)  would be accepted. 
C)  would fail to be rejected. 
D)  would become H0: $\mu$ $\neq$ 201

Question 17

A population is defined to be small if it is ____________________ than ____________________ times the size of the sample.

Accepted Answer

less; 20
l

Question 18

Assuming that all necessary conditions are met, what needs to be changed in the formula   so that we can use it to construct a (1 -$\alpha$) confidence interval estimate for the population proportion p?

Accepted Answer

A)  should be replaced by p. 
B)  t$\alpha$ should be replaced by z$\alpha$. 
C)  t$\alpha$should be replaced by t$\alpha$/ 2. 
D)  t$\alpha$ should be replaced by z$\alpha$ / 2. 
A)  should be replaced by p. 
B)  t$\alpha$ should be replaced by z$\alpha$. 
C)  t$\alpha$should be replaced by t$\alpha$/ 2. 
D)  t$\alpha$ should be replaced by z$\alpha$ / 2.

Question 19

Tractor Dealership
An accountant was performing an audit for a tractor dealership.An auditor wants to examine the monetary error made by the purchasing order department in the month of July.He decided to randomly sample 100 of the 925 purchase orders for the month of July, and found the amount of error in each one.The statistics for this sample were:   = $6.0 and s = $17.012.
-{Tractor Dealership Narrative} Estimate with 95% confidence the average amount of error per purchase order for the entire month of July.

Accepted Answer

@#IMG-DLM& LCL = $2.81, and UC

Question 20

When a population is small relative to the sample size, we must incorporate the ____________________ factor in the calculation of the standard error of estimate of the mean.

Accepted Answer

finite pop

When determining the sample size needed for a proportion for a given level of confidence and sampling error, the closer to 0.50 that p is estimated to be:

Sinus Drug A company claims that 10% of the users of a certain sinus drug experience drowsiness.In clinical studies of this sinus drug, 81 of the 900 subjects experienced drowsiness -{Sinus Drug Narrative} Explain how to use this confidence interval to test the hypotheses.

After calculating the sample size needed to estimate a population proportion to within 0.04, your statistics professor told you the maximum allowable error must be reduced to just .01.If the original calculation led to a sample size of 800, the sample size will now have to be:

Which of the following statements is false?

The test statistic used to test hypotheses about the population variance has a chi-squared distribution with ____________________ degrees of freedom.

Market segmentation separates consumers of a product into different groups in such a way that members of each group are similar to each other and there are differences between groups.

Which of the following would be an appropriate alternative hypothesis?

The area to the right of a certain critical value on a chi-squared distribution is 0.025.For 5 degrees of freedom, the critical value is 11.143.

Physicians A random sample of 200 physicians shows that there are 36 of them who make at least $400,000 a year. -{Physicians Narrative} Compute the p-value and explain how to use it to test the hypotheses.

Based on sample data, the 90% confidence interval limits for the population mean are LCL = 170.86 and UCL = 195.42.If the 10% level of significance were used in testing the hypotheses H₀: $\mu$ = 201 vs.H₁: $\mu$ $\neq$ 201, the null hypothesis:

A population is defined to be small if it is than times the size of the sample.

When a population is small relative to the sample size, we must incorporate the ____________________ factor in the calculation of the standard error of estimate of the mean.

What Is Statistics

Graphical Descriptive Techniques I

Graphical Descriptive Techniques II

Numerical Descriptive Techniques

Data Collection and Sampling

Probability

Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About Comparing Two Populations

Analysis of Variance

Chi-Squared Tests

Simple Linear Regression and Correlation

Multiple Regression

Filters

Exam 12: Inference About a Population

When determining the sample size needed for a proportion for a given level of confidence and sampling error, the closer to 0.50 that p is estimated to be:

The test statistic used to test hypotheses about the population variance is given by = (n- 1)s2 / σ\sigmaσ 2, which is chi-squared distributed with n - 1 degrees of freedom when the population random variable is normally distributed with variance equal to σ\sigmaσ 2.

Sinus Drug A company claims that 10% of the users of a certain sinus drug experience drowsiness.In clinical studies of this sinus drug, 81 of the 900 subjects experienced drowsiness -{Sinus Drug Narrative} Explain how to use this confidence interval to test the hypotheses.

After calculating the sample size needed to estimate a population proportion to within 0.04, your statistics professor told you the maximum allowable error must be reduced to just .01.If the original calculation led to a sample size of 800, the sample size will now have to be:

Which of the following statements is false?

The test statistic used to test hypotheses about the population variance has a chi-squared distribution with ____________________ degrees of freedom.

Market segmentation separates consumers of a product into different groups in such a way that members of each group are similar to each other and there are differences between groups.

Which of the following would be an appropriate alternative hypothesis?

The area to the right of a certain critical value on a chi-squared distribution is 0.025.For 5 degrees of freedom, the critical value is 11.143.

Physicians A random sample of 200 physicians shows that there are 36 of them who make at least $400,000 a year. -{Physicians Narrative} Compute the p-value and explain how to use it to test the hypotheses.

Based on sample data, the 90% confidence interval limits for the population mean are LCL = 170.86 and UCL = 195.42.If the 10% level of significance were used in testing the hypotheses H0: μ\muμ = 201 vs.H1: μ\muμ≠\neq= 201, the null hypothesis:

A population is defined to be small if it is ____________________ than ____________________ times the size of the sample.

Assuming that all necessary conditions are met, what needs to be changed in the formula so that we can use it to construct a (1 - α\alphaα ) confidence interval estimate for the population proportion p?

When a population is small relative to the sample size, we must incorporate the ____________________ factor in the calculation of the standard error of estimate of the mean.

What Is Statistics

Graphical Descriptive Techniques I

Graphical Descriptive Techniques II

Numerical Descriptive Techniques

Data Collection and Sampling

Probability

Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About Comparing Two Populations

Analysis of Variance

Chi-Squared Tests

Simple Linear Regression and Correlation

Multiple Regression

Filters

Based on sample data, the 90% confidence interval limits for the population mean are LCL = 170.86 and UCL = 195.42.If the 10% level of significance were used in testing the hypotheses H₀: $\mu$ = 201 vs.H₁: $\mu$ $\neq$ 201, the null hypothesis:

A population is defined to be small if it is than times the size of the sample.