Question

Subject: Statistics

Please show complete work for the multiple-choice questions below

1. If the standard deviation of a sample is 5 and each measurement in the
sample is doubled, the new value of s for the sample would be:
a. 2.5
b. 5
c. 7
d. 10

2. If the standard deviation of a sample is 5 and each measurement in the
sample is multiplied by 2, the new value of s for the sample would be:
a. 2.5
b. 5
c. 8
d. 10

3. On a statistics examination, an instructor finds that s = l4.0 for a sample of
undergraduate test scores and 7.0 for a sample of graduate test scores. Both
samples have the same number of students. Which of the following
statements is warranted?
a. The distribution is more likely to be symmetric among under-graduates
than graduate students.
b. Undergraduates are more heterogeneous in performance than graduate
students.
c. The average performance for graduates is higher than for undergraduates.
d. Undergraduates performed better than graduate students.

4. Which measure of dispersion is defined as the average squared deviation
from the mean?
a. population variance
b. population standard deviation
c. sample variance
d. sample standard deviation

5. If the mean of a sample is 80 and we add five points to each score, the mean
of the new sample is:
a. 80/5.
b. unchanged.
c. five points higher.
d. Insufficient information to answer.

Answer 1