Question 1

Suppose that a researcher selects a sample of participants from a population.If the shape of the distribution in this population is positively skewed,then what is the shape of the sampling distribution of sample means?

Accepted Answer

A) approximately positively skewed 
B) approximately negatively skewed 
C) approximately normally distributed 
D) There is not enough information to answer this question,because the population mean and variance are not given.

Question 2

A sampling distribution is a distribution of all sample means or sample variances that could be obtained in samples of a given size from the same population.

Accepted Answer

A) True 
 B)False

Question 3

A researcher selects a sample of size 4 from a population of size 6.How many possible samples of this size can be selected using experimental sampling?

Accepted Answer

A) 15 
B) 30 
C) 1,296 
D) 4,096

Question 4

A researcher selects a sample of 169 participants from a population with a mean of 50 and a standard deviation of 13.The probability of selecting a sample mean that is less than 49 is .8413.

Accepted Answer

A) True 
 B)False

Question 5

The standard error is the sample standard deviation divided by the square root of the sample size.

Accepted Answer

A) True 
 B)False

Question 6

The following samples were selected by two researchers.Which is associated with a smaller standard error of the mean?
Researcher A: n = 36,  = 12,  = 9
Researcher B: n = 36,  = 12,  = 6

Accepted Answer

A) Researcher A 
B) Researcher B 
C) They both have the same standard error.

Question 7

The sample mean is an unbiased estimator of the population mean.

Accepted Answer

A) True 
 B)False

Question 8

As sample size decreases,the standard error also decreases.

Accepted Answer

A) True 
 B)False

Question 9

A sampling distribution is a distribution of scores in a population.

Accepted Answer

A) True 
 B)False

Question 10

A researcher selects a sample of 9 participants from a population with a mean of 8 and a standard deviation of 3.About 14% of the sample means in this sampling distribution should be between a sample mean of

Accepted Answer

A) 6 and 8 
B) 5 and 6 
C) 9 and 10 
D) 10 and 11

Question 11

A researcher selects a sample of 100 participants from a population with a mean of 38 and a standard deviation of 20.About 68% of the sample means in this sampling distribution should be between a sample mean of

Accepted Answer

A) 34 and 40 
B) 34 and 38 
C) 38 and 44 
D) 36 and 40

Question 12

An articles states that a sample of 40 participants took 12 ± 2.3 (M ± SEM)seconds to complete a cognitive assessment.Which value is the standard error of the mean?

Accepted Answer

A) 40 
B) 12 
C) 2.3 
D) The standard error of the mean is not reported in the article

Question 13

Experimental research is typically conducted using a sampling strategy in which

Accepted Answer

A) the order of selecting participants matters 
B) the same participant can never be selected twice in the same sample 
C) participants are replaced after being sampled 
D) all of the above

Question 14

Each of the following statements are true,except that

Accepted Answer

A) increasing the sample size will decrease standard error 
B) the larger the sample size,the larger the standard error 
C) the larger the standard deviation in the population,the larger the standard error 
D) both B and C

Question 15

A researcher selects two samples of 25 participants each.In the first sample the population mean was 32 and the variance was 8.In this second sample,the population mean was 4 and the variance was 8.Which sample will be associated with a larger standard error of the mean?

Accepted Answer

A) Sample 1 
B) Sample 2 
C) None,both samples will have the same value for standard error 
D) There is not enough information to answer this question.

Question 16

There are 25 possible samples of size 2 that can be selected from a population of 5 people using theoretical sampling.

Accepted Answer

A) True 
 B)False

Question 17

Because the sampling distribution of sample means is normally distributed,we can use the z transformation formula to find probabilities.Which of the following gives the appropriate notation for this formula?

Accepted Answer

A)   
B)   
C)   
D) all of the above

Question 18

The sampling distribution of the mean has minimum variance.

Accepted Answer

A) True 
 B)False

Question 19

A researcher selects a sample of 625 participants from a population with a mean of 120 and a standard deviation of 25.The probability of selecting a sample mean that is larger than 125 is close to zero.

Accepted Answer

A) True 
 B)False

Question 20

A researcher selects from a participant pool of 4 males and 6 females.He determines that the probability of selecting 2 male participants is p = .16.Based on this probability,what strategy did the researcher use to sample participants.

Accepted Answer

A) sampling with replacement 
B) sampling without replacement

Exam 7: Probability and Sampling Distributions

Suppose that a researcher selects a sample of participants from a population.If the shape of the distribution in this population is positively skewed,then what is the shape of the sampling distribution of sample means?

A sampling distribution is a distribution of all sample means or sample variances that could be obtained in samples of a given size from the same population.

A researcher selects a sample of size 4 from a population of size 6.How many possible samples of this size can be selected using experimental sampling?

A researcher selects a sample of 169 participants from a population with a mean of 50 and a standard deviation of 13.The probability of selecting a sample mean that is less than 49 is .8413.

The standard error is the sample standard deviation divided by the square root of the sample size.

The following samples were selected by two researchers.Which is associated with a smaller standard error of the mean? Researcher A: n = 36, = 12, = 9 Researcher B: n = 36, = 12, = 6

The sample mean is an unbiased estimator of the population mean.

As sample size decreases,the standard error also decreases.

A sampling distribution is a distribution of scores in a population.

A researcher selects a sample of 9 participants from a population with a mean of 8 and a standard deviation of 3.About 14% of the sample means in this sampling distribution should be between a sample mean of

A researcher selects a sample of 100 participants from a population with a mean of 38 and a standard deviation of 20.About 68% of the sample means in this sampling distribution should be between a sample mean of

An articles states that a sample of 40 participants took 12 ± 2.3 (M ± SEM) seconds to complete a cognitive assessment.Which value is the standard error of the mean?

Experimental research is typically conducted using a sampling strategy in which

Each of the following statements are true,except that

A researcher selects two samples of 25 participants each.In the first sample the population mean was 32 and the variance was 8.In this second sample,the population mean was 4 and the variance was 8.Which sample will be associated with a larger standard error of the mean?

There are 25 possible samples of size 2 that can be selected from a population of 5 people using theoretical sampling.

Because the sampling distribution of sample means is normally distributed,we can use the z transformation formula to find probabilities.Which of the following gives the appropriate notation for this formula?

The sampling distribution of the mean has minimum variance.

A researcher selects a sample of 625 participants from a population with a mean of 120 and a standard deviation of 25.The probability of selecting a sample mean that is larger than 125 is close to zero.

A researcher selects from a participant pool of 4 males and 6 females.He determines that the probability of selecting 2 male participants is p = .16.Based on this probability,what strategy did the researcher use to sample participants.