A+ Answers



Question 1

A sample of n = 100 scores is selected from a population with  = 80 with  = 20.  On average, how much error is expected between the sample mean and the population mean?

Select one:

 a. 0.8 points

 b. 2 points

 c. 0.2 points

 d. 4 points

Question 2

For a normal population with µ = 40 and  = 10 which of the following samples is least likely to be obtained?

Select one:

 a. M + 44 for a sample of n = 4

 b. M + 44 for a sample of n = 100

 c. M + 42 for a sample of n = 100

 d. M + 42 for a sample of n = 4

Question 3

A sample of n = 16 scores is selected from a population with  = 100 and  = 32.  If the sample mean is M = 104, what is the z-score for this sample mean?

Select one:

 a. 1.00

 b. 2.00

 c. 0.25

 d. 0.50

Question 4

A random sample of n = 16 scores is obtained from a population with  = 12.  If the sample mean is 6 points greater than the population mean, what is the z-score for the sample mean?

Select one:

 a. +2.00

 b. +1.00

 c. It cannot be determined without knowing the population mean.

 d. +6.00

Question 5

A random sample of n = 36 scores is selected from a population.  Which of the following distributions definitely will be normal?

Select one:

 a. The scores in the population will form a normal distribution.

 b. Neither the sample, the population, nor the distribution of sample means will definitely be normal.

 c. The scores in the sample will form a normal distribution.

 d. The distribution of sample means will form a normal distribution.

Question 6

The distribution of sample means ____.

Select one:

 a. will be normal only if the sample size is at least n = 30

 b. will be normal only if the population distribution is normal

 c. will be normal if either the population is normal or the sample size is n > 30

 d. is always a normal distribution

Question 7

A sample of n = 9 scores is obtained from a population with  = 70 and  = 18.  If the sample mean is M = 76, then what is the z-score for the sample mean?

Select one:

 a. z = 1.00

 b. z = 0.33

 c. z = 0.50

 d. z = 3.00

Question 8

A sample from a population with  = 40 and  = 10 has a mean of M = 44.  If the sample mean corresponds to a z = 2.00, then how many scores are in the sample?

Select one:

 a. n = 100

 b. n = 5

 c. n = 4

 d. n = 25

Question 9

A random sample of n = 9 scores is obtained from a normal population with µ = 40 and  = 6.  What is the probability that the sample mean will be greater than M = 43?

Select one:

 a. 0.9332

 b. 0.6915

 c. 0.0668

 d. 0.3085

Question 10

A sample of n = 16 scores is obtained from a population with  = 50 and  = 16.  If the sample mean is M = 54, then what is the z-score for the sample mean?

Select one:

 a. z = 4.00

 b. z = 0.50

 c. z = 1.00

 d. z = 0.25

Question 11

If random samples, each with n = 36 scores, are selected from a normal population with µ = 80 and  = 18, how much difference, on average, should there be between a sample mean and the population mean?

Select one:

 a. 6 points

 b. 18 points

 c. 2 points

 d. 3 points

Question 12

Which combination of factors will produce the smallest value for the standard error?

Select one:

 a. A large sample and a large standard deviation

 b. A small sample and a large standard deviation

 c. A large sample and a small standard deviation

 d. A small sample and a small standard deviation

Question 13

A sample of n = 4 scores is selected from a population with  = 50 and  = 12.  If the sample mean is M = 56, what is the z-score for this sample mean?

Select one:

 a. 0.50

 b. 1.00

 c. 2.00

 d. 4.00

Question 14

A sample of n = 9 scores has a standard error of 6.  What is the standard deviation of the population from which the sample was obtained?

Select one:

 a. 2

 b. 6

 c. 54

 d. 18

Question 15

A sample is obtained from a population with  = 100 and  = 20.  Which of the following samples would produce the most extreme z-score?

Select one:

 a. A sample of n = 25 scores with M = 102

 b. A sample of n = 25 scores with M = 104

 c. A sample of n = 100 scores with M = 104

 d. A sample of n = 100 scores with M = 102