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