Assignment: Answer the following multiple choice:
1. One sample with n = 8 and a second sample with n = 10 will produce an independent-measures t statistic with df = 9. True or False
2. A researcher reports t(24) = 5.30 for an independent-measures experiment. How many individuals participated in the entire experiment? (Points: 1)
3. One sample of n = 5 scores has SS = 36. A second sample of n = 7 scores has SS = 64. What is the value of the pooled variance for these two samples?
c. 36/5 + 64/7
d. 36/4 + 64/6
The data from an independent-measures research study produce a sample mean difference of 4 points and a pooled variance of 12. If there are n = 6 scores in each sample, then the estimated standard error for the mean difference is _____. (Points: 1)
5. Two samples, each with n = 10 scores, are selected from the same population. If the variance for the first sample is s2 = 40 and the variance for the second sample is s2 = 50, then how much difference should be expected, on average, between the two sample means? (Points: 1)
a. 90 points
b. 45 points
c. 3 points
d. impossible to determine without additional information
6. The numerator of the repeated-measures t formula measures how much difference there is between the sample mean and the hypothesized population mean.
7. Compared to independent-measures designs, repeated-measures studies reduce the variance by removing individual differences. (Points: 1)
8. In general, an increase in variance for the sample of difference scores will cause _____.
a. an increase in the standard error and an increase in the value of t
b. an increase in the standard error and a decrease in the value of t
c. a decrease in the standard error and an increase in the value of t
d. a decrease in the standard error and a decrease in the value of t
9. With a= .05 and a sample of n = 15 participants in a repeated-measures study comparing two treatments, what are the t statistic boundaries for the two-tailed critical region? (Points: 1)
a. t = ±2.145
b. t = ±1.761
c. t = ±1.746
d. t = ±2.120
10. If a repeated-measures study shows a significant difference between two treatments with a = .01, then you can be sure that _____.
a. the value of Cohen’s d is large.
b. the percentage of variance explained (r2) is large
c. both Cohen’s d and r2 are large
c. A significant effect does not necessarily mean that the effect size will be large.