Statistics for Psychology, 7th Edition, Aron - Test
Bank - All Chapters Covered
With a t test for dependent means, Population 2 will ordinarily have a mean of: - ANSWERS0
In what important way does a t distribution differ from a normal curve? - ANSWERSit has slightly
more scores at the extremes
Another name for difference scores is: - ANSWERSChange scores
In the formula for estimating the population variance from the scores in a sample, the sum of
squared deviations is divided by: - ANSWERSthe number of participants in the sample minus
one
Approximately how many research participants would be required for 80% power for a study
using the t test for dependent means (assume a two-tailed hypothesis with an expected small
effect size of .20): - ANSWERS196
Gosset discovered the t distribution while attempting to: - ANSWERSimprove the quality of beer
for Guinness brewers
For the following question(s): A research article included the following table:
Mean Score on Four Questionnaire Scales Before and After the Experimental Manipulation
Which of the following differences was NOT statistically significant? - ANSWERSDominance
,In a study with 15 degrees of freedom, what would be your cutoff score for a t distribution using
a two-tailed test at the .01 level of significance? - ANSWERS2.947
A research article reports results of a study using a t test for dependent means as "t(16) = 2.67,
p < .05." This tells you: - ANSWERSthe t score was 2.67
The shape of a t distribution: - ANSWERSwill vary according to the degrees of freedom in the
sample you used to estimate population variance
Approximately how many research participants would be required for 80% power for a study
using the t test for dependent means (assume a one-tailed hypothesis with an expected
medium effect size of .50): - ANSWERS26
The estimated population variance is: - ANSWERSthe sum of squared deviation scores divided
by N − 1
What is often a limitation of research using a repeated-measure design? - ANSWERSlack of
control group
Suppose the counselor tested the null hypothesis that fourth graders in this class were less
depressed than those at the school generally. She figures her t score to be −.20. What decision
should she make regarding the null hypothesis? - ANSWERSFail to reject it
Other names for the t test for dependent means include all of the following EXCEPT: -
ANSWERSindependent-sample t test
You do a t test for dependent means in exactly the same way as a t test for a single sample,
except that you use something called: - ANSWERSdifference scores
, Which of the following is TRUE? - ANSWERSA sample's variance is a biased estimate of the
population's variance, but a slight change in the variance formula gives an unbiased estimate.
It takes a slightly __________ sample mean to get a significant result when using a t distribution
than when using a normal curve. - ANSWERSmore extreme
For the following question(s): A school counselor tests the level of depression in fourth graders
in a particular class of 20 students. The counselor wants to know whether the kind of students
in this class differs from that of fourth graders in general at her school. On the test, a score of 10
indicates severe depression, while a score of 0 indicates no depression. From reports, she is able
to find out about past testing. Fourth graders at her school usually score 5 on the scale, but the
variation is not known. Her sample of 20 fifth graders has a mean depression score of 4.4. Use
the .01 level of significance.
The counselor calculates the unbiased estimate of the population's variance to be 15. What is
the variance of the distribution of means? - ANSWERS15/20 = 0.75
A research article reports results of a study using a t test for dependent means as "t(38) = 3.11,
p < .01." This tells you: - ANSWERSthe result is statistically significant
A local newspaper reports that young women in your town (i.e., a known population) sleep an
average of only 5 hours per night. However, you think that women in your town who are
enrolled at your college sleep more than that. You randomly select 200 women from your
college and ask them to accurately record their hours of sleep. You find that they sleep an
average of 7 hours per night. What test would you use to determine whether this mean
difference is statistically meaningful? - ANSWERST test for a single sample
When utilizing t tests, __________ would be considered an adequate amount of power. -
ANSWERS80%
What can be said about the "Independence" difference score? - ANSWERSIt is statistically
significant at the .01 level
Bank - All Chapters Covered
With a t test for dependent means, Population 2 will ordinarily have a mean of: - ANSWERS0
In what important way does a t distribution differ from a normal curve? - ANSWERSit has slightly
more scores at the extremes
Another name for difference scores is: - ANSWERSChange scores
In the formula for estimating the population variance from the scores in a sample, the sum of
squared deviations is divided by: - ANSWERSthe number of participants in the sample minus
one
Approximately how many research participants would be required for 80% power for a study
using the t test for dependent means (assume a two-tailed hypothesis with an expected small
effect size of .20): - ANSWERS196
Gosset discovered the t distribution while attempting to: - ANSWERSimprove the quality of beer
for Guinness brewers
For the following question(s): A research article included the following table:
Mean Score on Four Questionnaire Scales Before and After the Experimental Manipulation
Which of the following differences was NOT statistically significant? - ANSWERSDominance
,In a study with 15 degrees of freedom, what would be your cutoff score for a t distribution using
a two-tailed test at the .01 level of significance? - ANSWERS2.947
A research article reports results of a study using a t test for dependent means as "t(16) = 2.67,
p < .05." This tells you: - ANSWERSthe t score was 2.67
The shape of a t distribution: - ANSWERSwill vary according to the degrees of freedom in the
sample you used to estimate population variance
Approximately how many research participants would be required for 80% power for a study
using the t test for dependent means (assume a one-tailed hypothesis with an expected
medium effect size of .50): - ANSWERS26
The estimated population variance is: - ANSWERSthe sum of squared deviation scores divided
by N − 1
What is often a limitation of research using a repeated-measure design? - ANSWERSlack of
control group
Suppose the counselor tested the null hypothesis that fourth graders in this class were less
depressed than those at the school generally. She figures her t score to be −.20. What decision
should she make regarding the null hypothesis? - ANSWERSFail to reject it
Other names for the t test for dependent means include all of the following EXCEPT: -
ANSWERSindependent-sample t test
You do a t test for dependent means in exactly the same way as a t test for a single sample,
except that you use something called: - ANSWERSdifference scores
, Which of the following is TRUE? - ANSWERSA sample's variance is a biased estimate of the
population's variance, but a slight change in the variance formula gives an unbiased estimate.
It takes a slightly __________ sample mean to get a significant result when using a t distribution
than when using a normal curve. - ANSWERSmore extreme
For the following question(s): A school counselor tests the level of depression in fourth graders
in a particular class of 20 students. The counselor wants to know whether the kind of students
in this class differs from that of fourth graders in general at her school. On the test, a score of 10
indicates severe depression, while a score of 0 indicates no depression. From reports, she is able
to find out about past testing. Fourth graders at her school usually score 5 on the scale, but the
variation is not known. Her sample of 20 fifth graders has a mean depression score of 4.4. Use
the .01 level of significance.
The counselor calculates the unbiased estimate of the population's variance to be 15. What is
the variance of the distribution of means? - ANSWERS15/20 = 0.75
A research article reports results of a study using a t test for dependent means as "t(38) = 3.11,
p < .01." This tells you: - ANSWERSthe result is statistically significant
A local newspaper reports that young women in your town (i.e., a known population) sleep an
average of only 5 hours per night. However, you think that women in your town who are
enrolled at your college sleep more than that. You randomly select 200 women from your
college and ask them to accurately record their hours of sleep. You find that they sleep an
average of 7 hours per night. What test would you use to determine whether this mean
difference is statistically meaningful? - ANSWERST test for a single sample
When utilizing t tests, __________ would be considered an adequate amount of power. -
ANSWERS80%
What can be said about the "Independence" difference score? - ANSWERSIt is statistically
significant at the .01 level
