Question 1

An unbiased estimator is a sample statistic:

Accepted Answer

A)  used to approximate a population parameter 
B)  which has an expected value equal to the value of the population parameter 
C)  whose value is usually less than the population parameter 
D)  that incorporates the standard error of the mean 
A)  used to approximate a population parameter 
B)  which has an expected value equal to the value of the population parameter 
C)  whose value is usually less than the population parameter 
D)  that incorporates the standard error of the mean B

Question 2

(A) Find the mean and standard deviation of the sampling distribution of the average weekly earnings in the sample.
(B) Find probability that the mean of the sample is less than $445.
(C) Find the probability that the mean of the sample is between $445 and $455.
(D) Find the probability that the mean of the sample is greater than $460.
(E) Explain why the assumption of normality about the distribution of the average weekly earnings for employees was not involved in the answers to (A) through (D).

Accepted Answer

(A) E(

(A) E( ) = = 450, and SE( ) = = 5 (B) P( < 445) = P(Z < -1) = 0.5000 - 0.3413 = 0.1587 (C) P(445< <455) = P(-1.0 < Z < 1.0) = 2(0.3413) = 0.6826 (D) P( > 460) = P(Z > 2.0) = 0.5000 - 0.4772 = 0.0228 (E) The sample size is large; n = 100 is greater than 30, so the distribution of the average weekly earnings for employees is at least approximately normal.

) =

= 450, and SE(

) =

= 5
(B) P(

< 445) = P(Z < -1) = 0.5000 - 0.3413 = 0.1587
(C) P(445<

<455) = P(-1.0 < Z < 1.0) = 2(0.3413) = 0.6826
(D) P(

> 460) = P(Z > 2.0) = 0.5000 - 0.4772 = 0.0228
(E) The sample size is large; n = 100 is greater than 30, so the distribution of the average weekly earnings for employees is at least approximately normal.

Question 3

The sampling distribution of any point estimate (such as the sample mean or proportion) is the distribution of the point estimates we would obtain from all possible samples of a given size drawn from the population.

Accepted Answer

A) True 
 B)False  True

Question 4

In stratified sampling, the population is divided into relatively homogeneous subsets called strata, and then random samples are taken from each stratum.

Accepted Answer

A) True 
 B)False

Question 5

When we sample less than 5% of the population, the finite population correction factor; fpc =   , is used to modify the formula for the standard error of the sample mean.

Accepted Answer

A) True 
 B)False

Question 6

A judgmental sample is a sample in which the:

Accepted Answer

A)  sampling units are chosen using a random number table 
B)  quality of sampling units judged before they are added to the sample 
C)  sampling units are chosen according to the sampler's judgment 
D)  sampling units are all biased and vocal about it 
A)  sampling units are chosen using a random number table 
B)  quality of sampling units judged before they are added to the sample 
C)  sampling units are chosen according to the sampler's judgment 
D)  sampling units are all biased and vocal about it

Question 7

In systematic sampling, one of the first k members is selected randomly, and then every kth member after this one is selected. The value k is called the sampling interval and equals the ratio N / n, where N is the population size and n is the desired sample size.

Accepted Answer

A) True 
 B)False

Question 8

The central limit theorem (CLT) is generally valid for:

Accepted Answer

A)  n > 5 
B)  n > 10 
C)  n > 20 
D)  n > 30 
E)  any size n 
A)  n > 5 
B)  n > 10 
C)  n > 20 
D)  n > 30 
E)  any size n

Question 9

The standard error of the estimate measures how much estimates vary from sample to sample.

Accepted Answer

A) True 
 B)False

Question 10

Auditors of Old Kent Bank are interested in comparing the reported value of customer savings account balances with their own findings regarding the actual value of such assets. Rather than reviewing the records of each savings account at the bank, the auditors decide to examine a representative sample of savings account balances. The frame from which they will sample is shown below.  
-(A) What sample size would be required for the auditors to be approximately 95% sure that their estimate of the average savings account balance at this bank is within $150 of the true mean? Assume that their best estimate of the population standard deviation   is $300.
(B) Choose a simple random sample of the size found in (A).
(C) Compute the observed sampling error based on the sample you have drawn from the population. How does the actual sampling error compare to the maximum possible probable absolute error established in (A)? Explain

Accepted Answer

(A) @#IMG-DLM& (B) The simple random sample of siz

Question 11

A probability sample is a sample in which the sampling units are chosen from the population by means of a random mechanism such as a random number table.

Accepted Answer

A) True 
 B)False

Question 12

The sampling distribution of the mean will have the same mean as the original population from which the samples were drawn.

Accepted Answer

A) True 
 B)False

Question 13

Which of the following is not a consideration when determining appropriate sample size?

Accepted Answer

A)  the cost of sampling 
B)  the timely collection of the data 
C)  interviewer fatigue 
D)  the likelihood of nonsampling error 
A)  the cost of sampling 
B)  the timely collection of the data 
C)  interviewer fatigue 
D)  the likelihood of nonsampling error

Question 14

Measurement error occurs when:

Accepted Answer

A)  a portion of the sample does not respond to the survey 
B)  the sample responses are not clear 
C)  the responses to question do not reflect what the investigator had in mind 
D)  the investigator does not correctly tally all responses 
A)  a portion of the sample does not respond to the survey 
B)  the sample responses are not clear 
C)  the responses to question do not reflect what the investigator had in mind 
D)  the investigator does not correctly tally all responses

Question 15

The sampling distribution of the mean will have the same standard deviation as the original population from which the samples were drawn.

Accepted Answer

A) True 
 B)False

Question 16

Non-truthful response is a particular problem when:

Accepted Answer

A)  sensitive questions are asked 
B)  surveys are anonymous 
C)  interviewers are not trained 
D)  the sample is from an unusual population 
A)  sensitive questions are asked 
B)  surveys are anonymous 
C)  interviewers are not trained 
D)  the sample is from an unusual population

Question 17

The averaging effect means that as you average more and more observations from a given distribution, the variance of the average:

Accepted Answer

A)  increases 
B)  decreases 
C)  is unaffected 
D)  could either increase, decrease, or stay the same 
A)  increases 
B)  decreases 
C)  is unaffected 
D)  could either increase, decrease, or stay the same

Question 18

The manager of a local fast-food restaurant is interested in improving service provided to customers who use the restaurant's drive-up window. As a first step in the process, the manager asks his assistant to record the time (in minutes) it takes to serve a large number of customers at the final window in the facility's drive-up system. The given frame in this case is 200 customer service times observed during the busiest hour of the day for this fast-food restaurant. The frame of 200 service times yielded a mean of 0.881. A simple random sample of 10 from this frame is presented below.  
-(A) Compute the point estimate of the population mean from the sample above. What is the sampling error in this case? Assume that the population consists of the given 200 customer service times.
(B) Compute the point estimate of the population standard deviation from the sample above.
(C) Should you use the finite population correction (fpc) factor to estimate the standard error of   ? Explain. If your answer is yes, what is the value of the fpc?
(D) Determine a good approximation to the standard error of the mean in this case.

Accepted Answer

(A) Sample mean @#IMG-DLM& = 0.96. Then, sampling

Question 19

A list of all members of the population from which we can choose a sample is called a frame, and the potential sample members are called sampling units.

Accepted Answer

A) True 
 B)False

Question 20

Simple random samples are samples in which each member of the population has the same chance of being chosen.

Accepted Answer

A) True 
 B)False

An unbiased estimator is a sample statistic:

The sampling distribution of any point estimate (such as the sample mean or proportion) is the distribution of the point estimates we would obtain from all possible samples of a given size drawn from the population.

In stratified sampling, the population is divided into relatively homogeneous subsets called strata, and then random samples are taken from each stratum.

When we sample less than 5% of the population, the finite population correction factor; fpc = , is used to modify the formula for the standard error of the sample mean.

A judgmental sample is a sample in which the:

In systematic sampling, one of the first k members is selected randomly, and then every k^th member after this one is selected. The value k is called the sampling interval and equals the ratio N / n, where N is the population size and n is the desired sample size.

The central limit theorem (CLT) is generally valid for:

The standard error of the estimate measures how much estimates vary from sample to sample.

A probability sample is a sample in which the sampling units are chosen from the population by means of a random mechanism such as a random number table.

The sampling distribution of the mean will have the same mean as the original population from which the samples were drawn.

Which of the following is not a consideration when determining appropriate sample size?

Measurement error occurs when:

The sampling distribution of the mean will have the same standard deviation as the original population from which the samples were drawn.

Non-truthful response is a particular problem when:

The averaging effect means that as you average more and more observations from a given distribution, the variance of the average:

A list of all members of the population from which we can choose a sample is called a frame, and the potential sample members are called sampling units.

Simple random samples are samples in which each member of the population has the same chance of being chosen.

Introduction to Business Analytics

Describing the Distribution of a Single Variable

Finding Relationships Among Variables

Probability and Probability Distributions

Normal, Binomial, Poisson, and Exponential Distributions

Decision Making Under Uncertainty

Confidence Interval Estimation

Hypothesis Testing

Regression Analysis: Estimating Relationships

Regression Analysis: Statistical Inference

Time Series Analysis and Forecasting

Introduction to Optimization Modeling

Optimization Models

Introduction to Simulation Modeling

Simulation Models

Data Mining

Importing Data Into Excel

Analysis of Variance and Experimental Design

Statistical Process Control

Filters

Exam 7: Sampling and Sampling Distributions

An unbiased estimator is a sample statistic:

The sampling distribution of any point estimate (such as the sample mean or proportion) is the distribution of the point estimates we would obtain from all possible samples of a given size drawn from the population.

In stratified sampling, the population is divided into relatively homogeneous subsets called strata, and then random samples are taken from each stratum.

When we sample less than 5% of the population, the finite population correction factor; fpc = , is used to modify the formula for the standard error of the sample mean.

A judgmental sample is a sample in which the:

In systematic sampling, one of the first k members is selected randomly, and then every kth member after this one is selected. The value k is called the sampling interval and equals the ratio N / n, where N is the population size and n is the desired sample size.

The central limit theorem (CLT) is generally valid for:

The standard error of the estimate measures how much estimates vary from sample to sample.

A probability sample is a sample in which the sampling units are chosen from the population by means of a random mechanism such as a random number table.

The sampling distribution of the mean will have the same mean as the original population from which the samples were drawn.

Which of the following is not a consideration when determining appropriate sample size?

Measurement error occurs when:

The sampling distribution of the mean will have the same standard deviation as the original population from which the samples were drawn.

Non-truthful response is a particular problem when:

The averaging effect means that as you average more and more observations from a given distribution, the variance of the average:

A list of all members of the population from which we can choose a sample is called a frame, and the potential sample members are called sampling units.

Simple random samples are samples in which each member of the population has the same chance of being chosen.

Introduction to Business Analytics

Describing the Distribution of a Single Variable

Finding Relationships Among Variables

Probability and Probability Distributions

Normal, Binomial, Poisson, and Exponential Distributions

Decision Making Under Uncertainty

Confidence Interval Estimation

Hypothesis Testing

Regression Analysis: Estimating Relationships

Regression Analysis: Statistical Inference

Time Series Analysis and Forecasting

Introduction to Optimization Modeling

Optimization Models

Introduction to Simulation Modeling

Simulation Models

Data Mining

Importing Data Into Excel

Analysis of Variance and Experimental Design

Statistical Process Control

Filters

In systematic sampling, one of the first k members is selected randomly, and then every k^th member after this one is selected. The value k is called the sampling interval and equals the ratio N / n, where N is the population size and n is the desired sample size.