When an ANOVA is conducted:

a) Fewer participants are required that when a t-test for independent means is conducted

b) Two estimates of the population variance compared

c) Difference scores are computed, as in the t-test for dependent means

d) All of the above

When conducting an analysis of variance if the null hypothesis is false, the:

a. the variation between sample means reflects the variation within the populations and the variation between the population means.

b. the within-group variance is significantly larger than the between-group variance.

c. the variance within each sample is larger than if the null hypothesis were true.

d. the variance between sample means is no greater than the variance within the population with the largest variance.

In an analysis of variance, the population variance can be estimated within any one group by:

a. finding the sum of squared deviations of the scores in that group from that group's mean, and dividing that sum by that group's degrees of freedom.

b. finding the sum of squared deviations of the scores in that group from that group's mean, and dividing that sum by the numerator degrees of freedom.

c. finding the sum of squared deviations of all the scores in that group from the overall mean of all the scores (in all groups), and dividing that sum by that group's degrees of freedom.

d. finding the sum of squared deviations of the scores in that group from the overall mean of all the scores (in all the groups), and dividing that sum by the numerator degrees of freedom.

6. For an analysis of variance, if the between-group estimate of the population variance is 30 and the within-group estimate is 25, then what is the F ratio?

A research article reports the following: "The mean performance scores for the Normal Sleep, Reduced Sleep, and No Sleep groups were 18.0, 16.6, and 15.6, respectively, F2, 36 = 2.95, p < 0.05. Based on this information, which conclusion is most accurate?

a. People who get no sleep perform significantly worse than people who sleep a reduced amount.

b. People who sleep reduced amount perform significantly worse than people are sleep a normal amount.

c. The three groups do not all come from populations with the same mean, although it is not clear which population means are different.

d. This study cannot conclude that amount of sleep is related to performance.