Selected Answer:
Pooled variance; variance
Answers:
Pooled variance; variance
Variance; pooled variance
Pooled variance; standard deviation
Standard deviation; pooled variance
Question 16
5 out of 5 points
There are three steps involved in creating the comparison distribution for the
independent-samples t test, and those steps are repeated many times. Which of
these is the sequence described in the text?
Selected Answer:
randomly select a group of scores and calculate their mean as the group 1 mean,
randomly select another group of scores and calculate their mean as the and group 2
mean, and subtract the second mean from the first.
Answers:
randomly select a pair of scores, subtract the second score from the first, and record
the difference between scores
randomly select a group of scores, calculate their mean, and plot that mean on a
distribution
randomly select a group of scores and calculate their mean as the group 1 mean,
randomly select another group of scores and calculate their mean as the and group 2
mean, and subtract the second mean from the first.
randomly select a score, subtract the mean from the score, and plot the difference
Question 17
5 out of 5 points
s2pooled is the symbol for:
Selected Answer:
pooled variance.
Answers:
variance.
pooled variance.
standard deviation.

pooled mean.
Question 18
5 out of 5 points
A study found statistically significant results for a hypothesis tested with an
independent-samples t test. The author of the study reported her effect size for the
test as 0.53. According to Cohen's convention, this effect size is considered:
Selected Answer:
medium.
Answers:
small.
medium.
large.
very large.
Question 19
0 out of 5 points
A psychologist is interested in whether working memory is influenced by sleep loss.
The psychologist administers a measure of working memory to two groups of
subjects. The subjects in one group were kept awake for the entire night and the
subjects in the other group maintained their normal sleep schedules. Which
statistical analysis should be performed to answer the question “Does sleep loss
affect working memory?”
Selected Answer:
paired-samples t test
Answers:
single-sample t test
z test
independent-samples t test
paired-samples t test
Question 20
0 out of 5 points
Dr. Jameson wanted to know if statistics exam scores differed between male and
female participants in his study. He gave 28 participants a statistics test and then
compared test scores for gender differences. He hypothesized that there would be a
statistically significant gender difference in test scores. Contrary to Dr. Jameson's
hypothesis, there were no differences in test scores between men and women in his
study. Based on the information provided, does this study meet the assumption of
normality? Why or why not?
Selected Answer:
No; it is not normally distributed because the small sample size is small.
Answers:
Yes; it is normally distributed because the sample size is large.