COMM 215 Chapter 7 Exam with 100% Solutions
MULTIPLE CHOICE QUESTIONS
In the following multiple choice questions, circle the correct answer.
1. Parameters are
a. numerical characteristics of a sample
b. numerical characteristics of a population
c. the averages taken from a sample
d. numerical characteristics of either a sample or a population
Answer: b
2. Sampling distribution of x is the
a. probability distribution of the sample mean
b. probability distribution of the sample proportion
c. mean of the sample
d. mean of the population
Answer: a
3. A simple random sample of 100 observations was taken from a large population. The sample mean
and the standard deviation were determined to be 80 and 12 respectively. The standard error of
the mean is
a. 1.20
b. 0.12
c. 8.00
d. 0.80
Answer: a
4. A population has a standard deviation of 16. If a sample of size 64 is selected from this
population, what is the probability that the sample mean will be within 2 of the population mean?
a. 0.6826
b. 0.3413
c. -0.6826
d. Since the mean is not given, there is no answer to this question.
Answer: a
5. The probability distribution of all possible values of the sample proportion p is the
a. probability density function of p
b. sampling distribution of x
c. same as p , since it considers all possible values of the sample proportion
d. sampling distribution of p
Answer: d
6. Convenience sampling is an example of
1
, 2 Chapter Seven
a. probabilistic sampling
b. stratified sampling
c. nonprobabilistic sampling
d. cluster sampling
Answer: c
7. Which of the following is an example of nonprobabilistic sampling?
a. simple random sampling
b. stratified simple random sampling
c. cluster sampling
d. judgment sampling
Answer: d
8. Stratified random sampling is a method of selecting a sample in which
a. the sample is first divided into strata, and then random samples are taken from each stratum
b. various strata are selected from the sample
c. the population is first divided into strata, and then random samples are drawn from each
stratum
d. None of these alternatives is correct.
Answer: c
9. A population consists of 500 elements. We want to draw a simple random sample of 50 elements
from this population. On the first selection, the probability of an element being selected is
a. 0.100
b. 0.010
c. 0.001
d. 0.002
Answer: d
10. The closer the sample mean is to the population mean,
a. the larger the sampling error
b. the smaller the sampling error
c. the sampling error equals 1
d. None of these alternatives is correct.
Answer: b
11. Since the sample size is always smaller than the size of the population, the sample mean
a. must always be smaller than the population mean
b. must be larger than the population mean
c. must be equal to the population mean
d. can be smaller, larger, or equal to the population mean
Answer: d
12. As the sample size increases, the
a. standard deviation of the population decreases
b. population mean increases
c. standard error of the mean decreases
d. standard error of the mean increases
MULTIPLE CHOICE QUESTIONS
In the following multiple choice questions, circle the correct answer.
1. Parameters are
a. numerical characteristics of a sample
b. numerical characteristics of a population
c. the averages taken from a sample
d. numerical characteristics of either a sample or a population
Answer: b
2. Sampling distribution of x is the
a. probability distribution of the sample mean
b. probability distribution of the sample proportion
c. mean of the sample
d. mean of the population
Answer: a
3. A simple random sample of 100 observations was taken from a large population. The sample mean
and the standard deviation were determined to be 80 and 12 respectively. The standard error of
the mean is
a. 1.20
b. 0.12
c. 8.00
d. 0.80
Answer: a
4. A population has a standard deviation of 16. If a sample of size 64 is selected from this
population, what is the probability that the sample mean will be within 2 of the population mean?
a. 0.6826
b. 0.3413
c. -0.6826
d. Since the mean is not given, there is no answer to this question.
Answer: a
5. The probability distribution of all possible values of the sample proportion p is the
a. probability density function of p
b. sampling distribution of x
c. same as p , since it considers all possible values of the sample proportion
d. sampling distribution of p
Answer: d
6. Convenience sampling is an example of
1
, 2 Chapter Seven
a. probabilistic sampling
b. stratified sampling
c. nonprobabilistic sampling
d. cluster sampling
Answer: c
7. Which of the following is an example of nonprobabilistic sampling?
a. simple random sampling
b. stratified simple random sampling
c. cluster sampling
d. judgment sampling
Answer: d
8. Stratified random sampling is a method of selecting a sample in which
a. the sample is first divided into strata, and then random samples are taken from each stratum
b. various strata are selected from the sample
c. the population is first divided into strata, and then random samples are drawn from each
stratum
d. None of these alternatives is correct.
Answer: c
9. A population consists of 500 elements. We want to draw a simple random sample of 50 elements
from this population. On the first selection, the probability of an element being selected is
a. 0.100
b. 0.010
c. 0.001
d. 0.002
Answer: d
10. The closer the sample mean is to the population mean,
a. the larger the sampling error
b. the smaller the sampling error
c. the sampling error equals 1
d. None of these alternatives is correct.
Answer: b
11. Since the sample size is always smaller than the size of the population, the sample mean
a. must always be smaller than the population mean
b. must be larger than the population mean
c. must be equal to the population mean
d. can be smaller, larger, or equal to the population mean
Answer: d
12. As the sample size increases, the
a. standard deviation of the population decreases
b. population mean increases
c. standard error of the mean decreases
d. standard error of the mean increases
