Question 1

Which of the following statements are correct?

Accepted Answer

A)   A point estimate is an estimate of the range of a population parameter
B)   A point estimate is a single value estimate of the value of a population parameter
C)   A point estimate is an unbiased estimator if its standard deviation is the same as the actual value of the population standard deviation
D)   All of these options

Question 2

The theorem that states that the sampling distribution of the sample mean  Xˉ\bar { X }Xˉ 
Is approximately normal when the sample size n is reasonably large is known as the:

Accepted Answer

A)   central limit theorem
B)   central tendency theorem
C)   simple random sample theorem
D)   point estimate theorem

Question 3

The reason the Central Limit Theorem (CLT) is such an important result in statistics is because:

Accepted Answer

A)   The CLT allows us to assume that the population distribution is approximately normal,provided n is reasonably large
B)   The CLT allows us to estimate the population mean without knowing the exact form of the population distribution,provided n is reasonably large
C)   The CLT allows us to construct confidence intervals for the population mean without knowing the exact form of the population distribution,provided n is reasonably large
D)   All of these options D

Question 4

The opportunity for nonsampling error is increased by:

Accepted Answer

A)   larger sample sizes
B)   smaller sample sizes
C)   affluent samples
D)   educated samples

Question 5

Simple random sampling can result in under-representation or over-representation of certain segments of the population.This is one of several reasons that simple random samples are almost never used in real applications.

Accepted Answer

A) True 
 B)False

Question 6

The sampling method in which a population is divided into blocks and then selected by choosing a random mechanism is called a

Accepted Answer

A)   random sampling
B)   systematic sampling
C)   stratified sampling
D)   cluster sampling B

Question 7

A sample in which the sampling units are chosen from the population by means of a random mechanism is a

Accepted Answer

A)   probability sample
B)   judgmental sample
C)   stratified sample
D)   systematic sample

Question 8

The size of a sample can be selected by first determining the desired standard error and then using the formula $S E ( X ) = \sigma I \sqrt { n }$ 
to calculate n.

Accepted Answer

A) True 
 B)False

Question 9

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  True

Question 10

The standard deviation of  Xˉ\bar { X }Xˉ 
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 11

The approximate standard error of the sample mean is calculated as:

Accepted Answer

A)   σIn\sigma I \sqrt { n }σInc-2.7,0,-7.17,-2.7,-13.5,-8c-5.8,-5.3,-9.5,-10,-9.5,-14c0,-2,0.3,-3.3,1,-4c1.3,-2.7,23.83,-20.7,67.5,-54c44.2,-33.3,65.8,-50.3,66.5,-51c1.3,-1.3,3,-2,5,-2c4.7,0,8.7,3.3,12,10s173,378,173,378c0.7,0,35.3,-71,104,-213c68.7,-142,137.5,-285,206.5,-429c69,-144,104.5,-217.7,106.5,-221l0 -0c5.3,-9.3,12,-14,20,-14H400000v40H845.2724s-225.272,467,-225.272,467s-235,486,-235,486c-2.7,4.7,-9,7,-19,7c-6,0,-10,-1,-12,-3s-194,-422,-194,-422s-65,47,-65,47zM834 80h400000v40h-400000z'/>​ 
B)   sIns I \sqrt { n }sInc-2.7,0,-7.17,-2.7,-13.5,-8c-5.8,-5.3,-9.5,-10,-9.5,-14c0,-2,0.3,-3.3,1,-4c1.3,-2.7,23.83,-20.7,67.5,-54c44.2,-33.3,65.8,-50.3,66.5,-51c1.3,-1.3,3,-2,5,-2c4.7,0,8.7,3.3,12,10s173,378,173,378c0.7,0,35.3,-71,104,-213c68.7,-142,137.5,-285,206.5,-429c69,-144,104.5,-217.7,106.5,-221l0 -0c5.3,-9.3,12,-14,20,-14H400000v40H845.2724s-225.272,467,-225.272,467s-235,486,-235,486c-2.7,4.7,-9,7,-19,7c-6,0,-10,-1,-12,-3s-194,-422,-194,-422s-65,47,-65,47zM834 80h400000v40h-400000z'/>​ 
C)   2σ/n2 \sigma/ \sqrt { n }2σ/nc-2.7,0,-7.17,-2.7,-13.5,-8c-5.8,-5.3,-9.5,-10,-9.5,-14c0,-2,0.3,-3.3,1,-4c1.3,-2.7,23.83,-20.7,67.5,-54c44.2,-33.3,65.8,-50.3,66.5,-51c1.3,-1.3,3,-2,5,-2c4.7,0,8.7,3.3,12,10s173,378,173,378c0.7,0,35.3,-71,104,-213c68.7,-142,137.5,-285,206.5,-429c69,-144,104.5,-217.7,106.5,-221l0 -0c5.3,-9.3,12,-14,20,-14H400000v40H845.2724s-225.272,467,-225.272,467s-235,486,-235,486c-2.7,4.7,-9,7,-19,7c-6,0,-10,-1,-12,-3s-194,-422,-194,-422s-65,47,-65,47zM834 80h400000v40h-400000z'/>​ 
D)   2s/n2 s / \sqrt { n }2s/nc-2.7,0,-7.17,-2.7,-13.5,-8c-5.8,-5.3,-9.5,-10,-9.5,-14c0,-2,0.3,-3.3,1,-4c1.3,-2.7,23.83,-20.7,67.5,-54c44.2,-33.3,65.8,-50.3,66.5,-51c1.3,-1.3,3,-2,5,-2c4.7,0,8.7,3.3,12,10s173,378,173,378c0.7,0,35.3,-71,104,-213c68.7,-142,137.5,-285,206.5,-429c69,-144,104.5,-217.7,106.5,-221l0 -0c5.3,-9.3,12,-14,20,-14H400000v40H845.2724s-225.272,467,-225.272,467s-235,486,-235,486c-2.7,4.7,-9,7,-19,7c-6,0,-10,-1,-12,-3s-194,-422,-194,-422s-65,47,-65,47zM834 80h400000v40h-400000z'/>​

Question 12

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 13

A point estimate is a single numeric value,a "best guess" of a population parameter,calculated from the sample data.

Accepted Answer

A) True 
 B)False

Question 14

The sampling mean  Xˉ\bar { X }Xˉ 
Is the estimate for the population mean  μ\muμ 
)

Accepted Answer

A)   random
B)   point
C)   simple
D)   interval

Question 15

An unbiased estimate is a point estimate such that the mean of its sampling distribution is equal to the true value of the population parameter being estimated.

Accepted Answer

A) True 
 B)False

Question 16

When a portion of the sample does not respond to the survey,results.

Accepted Answer

A)   measurement error
B)   nonresponse bias
C)   sampling error
D)   systematic failure
E)   nonlinear error

Question 17

It is customary to approximate the standard error of the sample mean $\sigma / \sqrt { n }$ 
by substituting the sample standard deviation s for $\sigma$ 
in the formula: SE( $\bar { X }$ 
)= $\sigma / \sqrt { n }$ 
.

Accepted Answer

A) True 
 B)False

Question 18

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 19

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 20

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

Exam 7: Sampling and Sampling Distributions

Which of the following statements are correct?

Correct AnswerverifiedShow Answer

The theorem that states that the sampling distribution of the sample mean Xˉ\bar { X }Xˉ Is approximately normal when the sample size n is reasonably large is known as the:

Correct AnswerverifiedShow Answer

The reason the Central Limit Theorem (CLT) is such an important result in statistics is because:

Correct AnswerverifiedD

The opportunity for nonsampling error is increased by:

Correct AnswerverifiedShow Answer

Simple random sampling can result in under-representation or over-representation of certain segments of the population.This is one of several reasons that simple random samples are almost never used in real applications.

Correct AnswerverifiedShow Answer

The sampling method in which a population is divided into blocks and then selected by choosing a random mechanism is called a

Correct AnswerverifiedB

A sample in which the sampling units are chosen from the population by means of a random mechanism is a

Correct AnswerverifiedShow Answer

The size of a sample can be selected by first determining the desired standard error and then using the formula SE(X)=σInS E ( X ) = \sigma I \sqrt { n }SE(X)=σIn​ to calculate n.

Correct AnswerverifiedShow Answer

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.

Correct AnswerverifiedTrue

The standard deviation of Xˉ\bar { X }Xˉ Is usually called the

Correct AnswerverifiedShow Answer

The approximate standard error of the sample mean is calculated as:

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

A point estimate is a single numeric value,a "best guess" of a population parameter,calculated from the sample data.

Correct AnswerverifiedShow Answer

The sampling mean Xˉ\bar { X }Xˉ Is the estimate for the population mean μ\muμ )

Correct AnswerverifiedShow Answer

An unbiased estimate is a point estimate such that the mean of its sampling distribution is equal to the true value of the population parameter being estimated.

Correct AnswerverifiedShow Answer

When a portion of the sample does not respond to the survey,results.

Correct AnswerverifiedShow Answer

It is customary to approximate the standard error of the sample mean σ/n\sigma / \sqrt { n }σ/n​ by substituting the sample standard deviation s for σ\sigmaσ in the formula: SE( Xˉ\bar { X }Xˉ )= σ/n\sigma / \sqrt { n }σ/n​ .

Correct AnswerverifiedShow Answer

The key to using stratified sampling is:

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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The theorem that states that the sampling distribution of the sample mean $\bar { X }$ Is approximately normal when the sample size n is reasonably large is known as the:

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D

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B

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The size of a sample can be selected by first determining the desired standard error and then using the formula $S E ( X ) = \sigma I \sqrt { n }$ to calculate n.

Correct Answer
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True

The standard deviation of $\bar { X }$ Is usually called the

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The sampling mean $\bar { X }$ Is the estimate for the population mean $\mu$ )

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It is customary to approximate the standard error of the sample mean $\sigma / \sqrt { n }$ by substituting the sample standard deviation s for $\sigma$ in the formula: SE( $\bar { X }$ )= $\sigma / \sqrt { n }$ .

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