Question 1

For a given population,the mean of all the sample means   ,of sample size n,and the mean of all (N)population observations (X)are ________.

Accepted Answer

A) equal to   
B) not equal 
C) equal to   - μ 
D) equal to the population mean µ 
A) equal to   
B) not equal 
C) equal to   - μ 
D) equal to the population mean µ

Question 2

If 40 samples of size 21 were selected from a population of 22,493,we would expect the mean of the sample means and the population mean to be close but not exactly equal.

Accepted Answer

A) True 
 B)False

Question 3

In stratified random sampling,a population is divided into strata using naturally occurring geographic or other boundaries. Then,strata are randomly selected and a random sample is collected from each strata.

Accepted Answer

A) True 
 B)False

Question 4

The tread life of tires mounted on light-duty trucks follows the normal probability distribution with a population mean of 60,000 miles and a population standard deviation of 4,000 miles. Suppose we select a sample of 40 tires and use a simulator to determine the tread life. What is the likelihood of finding that the sample mean is between 59,050 and 60,950?

Accepted Answer

A) 0.4332 
B) 0.8664 
C) 1.00 
D) Very likely 
A) 0.4332 
B) 0.8664 
C) 1.00 
D) Very likely

Question 5

When doing research,knowing the population mean and other population parameters is essential.

Accepted Answer

A) True 
 B)False

Question 6

When all the items in a population have an equal chance of being selected for a sample,the process is called ________.

Accepted Answer

A) simple random sampling 
B) z-score 
C) sampling error 
D) nonprobability sampling 
A) simple random sampling 
B) z-score 
C) sampling error 
D) nonprobability sampling

Question 7

The tread life of tires mounted on light-duty trucks follows the normal probability distribution with a population mean of 60,000 miles and a population standard deviation of 4,000 miles. Suppose you bought a set of four tires; what is the likelihood the mean tire life of these four tires is more than 66,000 miles?

Accepted Answer

A) 0.0013 
B) 0.9987 
C) 0.4987 
D) 0.9544 
A) 0.0013 
B) 0.9987 
C) 0.4987 
D) 0.9544

Question 8

The standard error of the mean measures the dispersion of the sampling distribution of the sample mean.

Accepted Answer

A) True 
 B)False

Question 9

The standard error of the mean is directly related to the sample size.

Accepted Answer

A) True 
 B)False

Question 10

The size of the sampling error is ________.

Accepted Answer

A) directly related to the sample size-in other words,the larger the sample size,the larger the sampling error 
B) directly related to the population mean-in other words,the larger the mean,the larger the sampling error 
C) inversely related to the sample size-in other words,the larger the sample size,the smaller the sampling error 
D) inversely related to the population standard deviation-in other words,the smaller the standard deviation,the larger the sampling error 
A) directly related to the sample size-in other words,the larger the sample size,the larger the sampling error 
B) directly related to the population mean-in other words,the larger the mean,the larger the sampling error 
C) inversely related to the sample size-in other words,the larger the sample size,the smaller the sampling error 
D) inversely related to the population standard deviation-in other words,the smaller the standard deviation,the larger the sampling error

Question 11

When using stratified random sampling,the sampling error will be zero.

Accepted Answer

A) True 
 B)False

Question 12

Which of the following is the standard error of the mean?

Accepted Answer

A) σ 
B) x/n 
C) σ /   
D) s 
A) σ 
B) x/n 
C) σ /   
D) s

Question 13

The Office of Student Services at a large western state university maintains information on the study habits of its full-time students. Their studies indicate that the mean amount of time undergraduate students study per week is 20 hours. The hours studied follows the normal distribution with a population standard deviation of six hours. Suppose we select a random sample of 144 current students. What is the probability that the mean of this sample is less than 19.25 hours?

Accepted Answer

A) 0.4332 
B) 0.8664 
C) 0.0668 
D) 0.0181 
A) 0.4332 
B) 0.8664 
C) 0.0668 
D) 0.0181

Question 14

The Office of Student Services at a large western state university maintains information on the study habits of its full-time students. Their studies indicate that the mean amount of time undergraduate students study per week is 20 hours. The hours studied follows the normal distribution with a population standard deviation of six hours. Suppose we select a random sample of 144 current students. What is the probability that the mean of this sample is between 19 hours and 20 hours?

Accepted Answer

A) 2.00 
B) 0.4772 
C) −2.00 
D) Cannot be calculated based on the given information. 
A) 2.00 
B) 0.4772 
C) −2.00 
D) Cannot be calculated based on the given information.

Question 15

What is the difference between a sample mean and the population mean called?

Accepted Answer

A) Standard error of the mean 
B) Sampling error 
C) Interval estimate 
D) Point estimate 
A) Standard error of the mean 
B) Sampling error 
C) Interval estimate 
D) Point estimate

Question 16

The tread life of tires mounted on light-duty trucks follows the normal probability distribution with a population mean of 60,000 miles and a population standard deviation of 4,000 miles. Suppose we select a sample of 40 tires and use a simulator to determine the tread life. What is the standard error of the mean?

Accepted Answer

A) 632.46 
B) 40 
C) 4,000 
D) Cannot be determined. 
A) 632.46 
B) 40 
C) 4,000 
D) Cannot be determined.

Question 17

The Intelligence Quotient (IQ)test scores for adults are normally distributed with a population mean of 100 and a population standard deviation of 15. What is the probability we could select a sample of 50 adults and find the mean of this sample is between 95 and 105?

Accepted Answer

A) 0.0182 
B) 0.9818 
C) 1.00 
D) Very unlikely 
A) 0.0182 
B) 0.9818 
C) 1.00 
D) Very unlikely

Question 18

The Intelligence Quotient (IQ)test scores for adults are normally distributed with a population mean of 100 and a population standard deviation of 15. What is the probability we could select a sample of 50 adults and find that the mean of this sample exceeds 104?

Accepted Answer

A) 0.0294 
B) 0.9412 
C) Approximately 1 
D) 0.9706 
A) 0.0294 
B) 0.9412 
C) Approximately 1 
D) 0.9706

Question 19

According to the central limit theorem,________.

Accepted Answer

A) the population mean and the mean of all sample means are equal 
B) increasing sample size decreases the dispersion of the sampling distribution 
C) the sampling distribution of the sample means is approximately normally distributed 
D) the sampling distribution of the sample means will be skewed 
A) the population mean and the mean of all sample means are equal 
B) increasing sample size decreases the dispersion of the sampling distribution 
C) the sampling distribution of the sample means is approximately normally distributed 
D) the sampling distribution of the sample means will be skewed

Question 20

As the size of the sample increases,what happens to the shape of the distribution of sample means?

Accepted Answer

A) It cannot be predicted in advance. 
B) It approaches a normal distribution. 
C) It is positively skewed. 
D) It is negatively skewed. 
A) It cannot be predicted in advance. 
B) It approaches a normal distribution. 
C) It is positively skewed. 
D) It is negatively skewed.

For a given population,the mean of all the sample means ,of sample size n,and the mean of all (N)population observations (X)are ________.

If 40 samples of size 21 were selected from a population of 22,493,we would expect the mean of the sample means and the population mean to be close but not exactly equal.

In stratified random sampling,a population is divided into strata using naturally occurring geographic or other boundaries. Then,strata are randomly selected and a random sample is collected from each strata.

When doing research,knowing the population mean and other population parameters is essential.

When all the items in a population have an equal chance of being selected for a sample,the process is called ________.

The standard error of the mean measures the dispersion of the sampling distribution of the sample mean.

The standard error of the mean is directly related to the sample size.

The size of the sampling error is ________.

When using stratified random sampling,the sampling error will be zero.

Which of the following is the standard error of the mean?

What is the difference between a sample mean and the population mean called?

The Intelligence Quotient (IQ)test scores for adults are normally distributed with a population mean of 100 and a population standard deviation of 15. What is the probability we could select a sample of 50 adults and find the mean of this sample is between 95 and 105?

The Intelligence Quotient (IQ)test scores for adults are normally distributed with a population mean of 100 and a population standard deviation of 15. What is the probability we could select a sample of 50 adults and find that the mean of this sample exceeds 104?

According to the central limit theorem,________.

As the size of the sample increases,what happens to the shape of the distribution of sample means?

What Is Statistics

Describing Data: Frequency Tables, Frequency Distributions, and Graphic Presentation

Describing Data: Numerical Measures

Describing Data: Displaying and Exploring Data

A Survey of Probability Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Estimation and Confidence Intervals

One-Sample Tests of Hypothesis

Two-Sample Tests of Hypothesis

Analysis of Variance

Correlation and Linear Regression

Multiple Regression Analysis

Nonparametric Methods: Nominal Level Hypothesis Tests

Nonparametric Methods: Analysis of Ordinal Data

Index Numbers

Time Series and Forecasting

Statistical Process Control and Quality Management

An Introduction to Decision Theory

Filters

Exam 8: Sampling Methods and the Central Limit Theorem

For a given population,the mean of all the sample means ,of sample size n,and the mean of all (N)population observations (X)are ________.

If 40 samples of size 21 were selected from a population of 22,493,we would expect the mean of the sample means and the population mean to be close but not exactly equal.

In stratified random sampling,a population is divided into strata using naturally occurring geographic or other boundaries. Then,strata are randomly selected and a random sample is collected from each strata.

When doing research,knowing the population mean and other population parameters is essential.

When all the items in a population have an equal chance of being selected for a sample,the process is called ________.

The standard error of the mean measures the dispersion of the sampling distribution of the sample mean.

The standard error of the mean is directly related to the sample size.

The size of the sampling error is ________.

When using stratified random sampling,the sampling error will be zero.

Which of the following is the standard error of the mean?

What is the difference between a sample mean and the population mean called?

The Intelligence Quotient (IQ)test scores for adults are normally distributed with a population mean of 100 and a population standard deviation of 15. What is the probability we could select a sample of 50 adults and find the mean of this sample is between 95 and 105?

The Intelligence Quotient (IQ)test scores for adults are normally distributed with a population mean of 100 and a population standard deviation of 15. What is the probability we could select a sample of 50 adults and find that the mean of this sample exceeds 104?

According to the central limit theorem,________.

As the size of the sample increases,what happens to the shape of the distribution of sample means?

What Is Statistics

Describing Data: Frequency Tables, Frequency Distributions, and Graphic Presentation

Describing Data: Numerical Measures

Describing Data: Displaying and Exploring Data

A Survey of Probability Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Estimation and Confidence Intervals

One-Sample Tests of Hypothesis

Two-Sample Tests of Hypothesis

Analysis of Variance

Correlation and Linear Regression

Multiple Regression Analysis

Nonparametric Methods: Nominal Level Hypothesis Tests

Nonparametric Methods: Analysis of Ordinal Data

Index Numbers

Time Series and Forecasting

Statistical Process Control and Quality Management

An Introduction to Decision Theory

Filters