Question 1

The standard deviation of  is usually called the

Accepted Answer

A) standard error of the mean 
B) standard error of the sample 
C) standard error of the population 
D) randomized standard error

Question 2

The Central Limit Theorem (CLT)states that the sampling distribution of the mean is approximately normal,no matter what the distribution of the population,so long as the sample size is large enough.

Accepted Answer

A) True 
 B)False

Question 3

(A)What sample size would be required for the production personnel to be approximately 95% sure that their estimate of the average number of defective batteries per box is within 0.3 unit of the true mean? Assume that the best estimate of the population standard deviation (  )is 0.9 defective batteries per box.
(B)How does your answer to (A)change if the production personnel want their estimate to be within 0.5 unit of the actual population mean? Evaluate the tradeoff between required accuracy and sample size requirement for this case and the case in (A).

Accepted Answer

The answer of (A)What sample size would be required for...

Question 4

Estimation is the process of inferring the value of an unknown population parameter using data from a random sample

Accepted Answer

A) True 
 B)False

Question 5

In sampling,a population is:

Accepted Answer

A) the set of all humans 
B) the set of all members about which a study intends to make inferences 
C) any group of test subjects 
D) a random group of individuals,households,cities or countries

Question 6

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 7

(A)Suppose that Sally wishes to examine a representative subset of these 60 houses that has been stratified by the number of bedrooms.Use Excel to assist her by finding such a stratified sample of size 10 with proportional sample sizes.
(B)Explain how Sally could apply cluster sampling in selecting a sample of size 15 from this frame.
(C)What are the advantages and disadvantages of employing cluster sampling in this case?

Accepted Answer

The answer of (A)Suppose that Sally wishes to examine a...

Question 8

One obvious advantage of stratified sampling is that we obtain separate estimates within each stratum - which we would not obtain if we took a simple random sample from the entire population.A more important advantage is that we can increase the accuracy of the resulting population estimates by using appropriately defined strata.

Accepted Answer

A) True 
 B)False

Question 9

The key to using stratified sampling is:

Accepted Answer

A) identifying the strata 
B) selecting the appropriate strata 
C) defining the strata 
D) randomizing the strata

Question 10

The standard error of sample mean  is large when the observations in the population are spread out (large  ),but that the standard error can be reduced by taking a smaller sample.

Accepted Answer

A) True 
 B)False

Question 11

A sample chosen in such a way that every possible subset of same size has an equal chance of being selected is called a(n)

Accepted Answer

A) interval estimation 
B) point estimation 
C) simple random sample. 
D) statistic

Question 12

The standard error of an estimate is the standard deviation of the sampling distribution of the estimate.It measures how much estimates from different samples vary.

Accepted Answer

A) True 
 B)False

Question 13

With proportional sample sizes:

Accepted Answer

A) The proportion of a stratum in the sample is independent of the proportion of that stratum in the population 
B) The proportion of a stratum in the sample is the same as the proportion of that stratum in the population 
C) The proportion of a stratum in the sample is greater than the proportion of that stratum in the population 
D) The proportion of a stratum in the sample is less than the proportion of that stratum in the population

Question 14

The randomized response technique is a way of getting at sensitive information to avoid estimation errors due to nontruthful responses.

Accepted Answer

A) True 
 B)False

Question 15

We can measure the accuracy of judgmental samples by applying some simple rules of probability.This way,judgmental samples are not likely to contain our built-in biases.

Accepted Answer

A) True 
 B)False

Question 16

Which of the following are reasons for why simple random sampling is used infrequently in real applications?

Accepted Answer

A) Samples can be spread over a large geographic region 
B) Simple random sampling requires that all sampling units be identified prior to sampling 
C) Simple random sampling can result in underrepresentation or overrepresentation of certain segments of the population 
D) All of these options

Question 17

An estimator is said to be unbiased if the mean of its sampling distribution equals the value of the population parameter being estimated.

Accepted Answer

A) True 
 B)False

Question 18

If systematic sampling is chosen as the sampling technique,it is probably because:

Accepted Answer

A) Systematic sampling has better statistical properties than simple random sampling 
B) Systematic sampling is more convenient 
C) Systematic sampling always results in more representative sampling than simple random sampling 
D) None of these options

Question 19

The defining property of a simple random sample is that:

Accepted Answer

A) every sample has the same chance of being chosen 
B) the easiest method to access samples are chosen 
C) the fewest samples are chosen 
D) every fourth subject is chosen as a sample

Question 20

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

Exam 7: Sampling and Sampling Distributions

The standard deviation of is usually called the

The Central Limit Theorem (CLT)states that the sampling distribution of the mean is approximately normal,no matter what the distribution of the population,so long as the sample size is large enough.

Estimation is the process of inferring the value of an unknown population parameter using data from a random sample

In sampling,a population is:

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.

The key to using stratified sampling is:

The standard error of sample mean is large when the observations in the population are spread out (large ),but that the standard error can be reduced by taking a smaller sample.

A sample chosen in such a way that every possible subset of same size has an equal chance of being selected is called a(n)

The standard error of an estimate is the standard deviation of the sampling distribution of the estimate.It measures how much estimates from different samples vary.

With proportional sample sizes:

The randomized response technique is a way of getting at sensitive information to avoid estimation errors due to nontruthful responses.

We can measure the accuracy of judgmental samples by applying some simple rules of probability.This way,judgmental samples are not likely to contain our built-in biases.

Which of the following are reasons for why simple random sampling is used infrequently in real applications?

An estimator is said to be unbiased if the mean of its sampling distribution equals the value of the population parameter being estimated.

If systematic sampling is chosen as the sampling technique,it is probably because:

The defining property of a simple random sample is that:

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