Question 1

In a sample size calculation,if the confidence level decreases,the size of the sample needed will increase.

Accepted Answer

A) True 
 B)False  False

Question 2

A 99 percent confidence interval has more confidence but less precision than a 95 percent confidence interval.

Accepted Answer

A) True 
 B)False  True

Question 3

Approximately 95 percent of the population X values will lie within the 95 percent confidence interval for the mean.

Accepted Answer

A) True 
 B)False  False

Question 4

The expected value of an unbiased estimator is equal to the parameter whose value is being estimated.

Accepted Answer

A) True 
 B)False

Question 5

The sample mean is not a random variable when the population parameters are known.

Accepted Answer

A) True 
 B)False

Question 6

In a random sample of 810 women employees,it is found that 81 would prefer working for a female boss.The width of the 95 percent confidence interval for the proportion of women who prefer a female boss is:

Accepted Answer

A)  ± .0288 
B)  ± .0105 
C)  ± .0207 
D)  ± .0196 
A)  ± .0288 
B)  ± .0105 
C)  ± .0207 
D)  ± .0196

Question 7

In comparing estimators,the more efficient estimator will have a smaller standard error.

Accepted Answer

A) True 
 B)False

Question 8

The owner of Torpid Oaks B&B wanted to know the average distance its guests had traveled.A random sample of 16 guests showed a mean distance of 85 miles with a standard deviation of 32 miles.The 90 percent confidence interval (in miles)for the mean is approximately:

Accepted Answer

A)  (71.0,99.0) 
B)  (71.8,98.2) 
C)  (74.3,95.7) 
D)  (68.7,103.2) 
A)  (71.0,99.0) 
B)  (71.8,98.2) 
C)  (74.3,95.7) 
D)  (68.7,103.2)

Question 9

The finite population correction factor (FPCF)can be ignored if n = 7 and N = 700.

Accepted Answer

A) True 
 B)False

Question 10

A sampling distribution describes the distribution of:

Accepted Answer

A)  a parameter. 
B)  a statistic. 
C)  either a parameter or a statistic. 
D)  neither a parameter nor a statistic. 
A)  a parameter. 
B)  a statistic. 
C)  either a parameter or a statistic. 
D)  neither a parameter nor a statistic.

Question 11

In which situation may the sample proportion safely be assumed to follow a normal distribution?

Accepted Answer

A)  12 successes in a sample of 72 items 
B)  8 successes in a sample of 40 items 
C)  6 successes in a sample of 200 items 
D)  4 successes in a sample of 500 items 
A)  12 successes in a sample of 72 items 
B)  8 successes in a sample of 40 items 
C)  6 successes in a sample of 200 items 
D)  4 successes in a sample of 500 items

Question 12

To estimate the required sample size for a proportion,one method is to take a small pilot sample to estimate π and then apply the sample size formula.

Accepted Answer

A) True 
 B)False

Question 13

Jolly Blue Giant Health Insurance (JBGHI)is concerned about rising lab test costs and would like to know what proportion of the positive lab tests for prostate cancer are actually proven correct through subsequent biopsy.JBGHI demands a sample large enough to ensure an error of ± 2 percent with 90 percent confidence.What is the necessary sample size?

Accepted Answer

A)  4,148 
B)  2,401 
C)  1,692 
D)  1,604 
A)  4,148 
B)  2,401 
C)  1,692 
D)  1,604

Question 14

In which situation may the sample proportion safely be assumed to follow a normal distribution?

Accepted Answer

A)  n = 100,π = .06 
B)  n = 250,π = .02 
C)  n = 30,π = .50 
D)  n = 500,π = .01 
A)  n = 100,π = .06 
B)  n = 250,π = .02 
C)  n = 30,π = .50 
D)  n = 500,π = .01

Question 15

Which of the following statements is most nearly correct,other things being equal?

Accepted Answer

A)  Using Student's t instead of z makes a confidence interval narrower. 
B)  The table values of z and t are about the same when the mean is large. 
C)  For a given confidence level,the z value is always smaller then the t value. 
D)  Student's t is rarely used because it is more conservative to use z. 
A)  Using Student's t instead of z makes a confidence interval narrower. 
B)  The table values of z and t are about the same when the mean is large. 
C)  For a given confidence level,the z value is always smaller then the t value. 
D)  Student's t is rarely used because it is more conservative to use z.

Question 16

A consistent estimator for the mean:

Accepted Answer

A)  converges on the true parameter μ as the variance increases. 
B)  converges on the true parameter μ as the sample size increases. 
C)  consistently follows a normal distribution. 
D)  is impossible to obtain using real sample data. 
A)  converges on the true parameter μ as the variance increases. 
B)  converges on the true parameter μ as the sample size increases. 
C)  consistently follows a normal distribution. 
D)  is impossible to obtain using real sample data.

Question 17

List differences and similarities between Student's t and the standard normal distribution.

Accepted Answer

Both are bell-shaped and symme

Question 18

Sampling error can be avoided:

Accepted Answer

A)  by using an unbiased estimator. 
B)  by eliminating nonresponses (e.g. ,older people). 
C)  by no method under the statistician's control. 
D)  either by using an unbiased estimator or by eliminating nonresponse. 
A)  by using an unbiased estimator. 
B)  by eliminating nonresponses (e.g. ,older people). 
C)  by no method under the statistician's control. 
D)  either by using an unbiased estimator or by eliminating nonresponse.

Question 19

As n increases,the width of the confidence interval will decrease,ceteris paribus.

Accepted Answer

A) True 
 B)False

Question 20

The standard error of the mean decreases when:

Accepted Answer

A)  the sample size decreases. 
B)  the standard deviation increases. 
C)  the standard deviation decreases or n increases. 
D)  the population size decreases. 
A)  the sample size decreases. 
B)  the standard deviation increases. 
C)  the standard deviation decreases or n increases. 
D)  the population size decreases.

In a sample size calculation,if the confidence level decreases,the size of the sample needed will increase.

A 99 percent confidence interval has more confidence but less precision than a 95 percent confidence interval.

Approximately 95 percent of the population X values will lie within the 95 percent confidence interval for the mean.

The expected value of an unbiased estimator is equal to the parameter whose value is being estimated.

The sample mean is not a random variable when the population parameters are known.

In a random sample of 810 women employees,it is found that 81 would prefer working for a female boss.The width of the 95 percent confidence interval for the proportion of women who prefer a female boss is:

In comparing estimators,the more efficient estimator will have a smaller standard error.

The owner of Torpid Oaks B&B wanted to know the average distance its guests had traveled.A random sample of 16 guests showed a mean distance of 85 miles with a standard deviation of 32 miles.The 90 percent confidence interval (in miles)for the mean is approximately:

The finite population correction factor (FPCF)can be ignored if n = 7 and N = 700.

A sampling distribution describes the distribution of:

In which situation may the sample proportion safely be assumed to follow a normal distribution?

To estimate the required sample size for a proportion,one method is to take a small pilot sample to estimate π and then apply the sample size formula.

In which situation may the sample proportion safely be assumed to follow a normal distribution?

Which of the following statements is most nearly correct,other things being equal?

A consistent estimator for the mean:

List differences and similarities between Student's t and the standard normal distribution.

Sampling error can be avoided:

As n increases,the width of the confidence interval will decrease,ceteris paribus.

The standard error of the mean decreases when:

Overview of Statistics

Data Collection

Describing Data Visually

Descriptive Statistics

Probability

Discrete Probability Distributions

Continuous Probability Distributions

One-Sample Hypothesis Tests

Two-Sample Hypothesis Tests

Analysis of Variance

Simple Regression

Multiple Regression

Time-Series Analysis

Chi-Square Tests

Nonparametric Tests

Quality Management

Filters

Exam 8: Sampling Distributions and Estimation

In a sample size calculation,if the confidence level decreases,the size of the sample needed will increase.

A 99 percent confidence interval has more confidence but less precision than a 95 percent confidence interval.

Approximately 95 percent of the population X values will lie within the 95 percent confidence interval for the mean.

The expected value of an unbiased estimator is equal to the parameter whose value is being estimated.

The sample mean is not a random variable when the population parameters are known.

In a random sample of 810 women employees,it is found that 81 would prefer working for a female boss.The width of the 95 percent confidence interval for the proportion of women who prefer a female boss is:

In comparing estimators,the more efficient estimator will have a smaller standard error.

The owner of Torpid Oaks B&B wanted to know the average distance its guests had traveled.A random sample of 16 guests showed a mean distance of 85 miles with a standard deviation of 32 miles.The 90 percent confidence interval (in miles)for the mean is approximately:

The finite population correction factor (FPCF)can be ignored if n = 7 and N = 700.

A sampling distribution describes the distribution of:

In which situation may the sample proportion safely be assumed to follow a normal distribution?

To estimate the required sample size for a proportion,one method is to take a small pilot sample to estimate π and then apply the sample size formula.

In which situation may the sample proportion safely be assumed to follow a normal distribution?

Which of the following statements is most nearly correct,other things being equal?

A consistent estimator for the mean:

List differences and similarities between Student's t and the standard normal distribution.

Sampling error can be avoided:

As n increases,the width of the confidence interval will decrease,ceteris paribus.

The standard error of the mean decreases when:

Overview of Statistics

Data Collection

Describing Data Visually

Descriptive Statistics

Probability

Discrete Probability Distributions

Continuous Probability Distributions

One-Sample Hypothesis Tests

Two-Sample Hypothesis Tests

Analysis of Variance

Simple Regression

Multiple Regression

Time-Series Analysis

Chi-Square Tests

Nonparametric Tests

Quality Management

Filters