Question: A study conducted a series of experiments examining the effects of humor on memory. They collected a set of humorous sentences and the modified each one to produce nonhumorous version of the same sentence. the humorous sentences were them presented to one group of participants and the nonhumorous sentences were presented to another group. Each group was then given a test to determine how many sentences they could recall. Data similar to those obtained by the study are shown in the following table.

_____________________________________________

_____ Number of sentences recalled_______________

Humorous sentences______________Nonhumorous sentences

4 5 2 4 5 2 4 2

6 7 6 6 2 3 1 5

2 5 4 3 3 2 3 3

3 3 5 3 4 1 5 3

(a) Does the data provide enough evidence to conclude that humor has a significant effect on memory? Use a two-tailed test at the .05 level of significance.

(b) Calculate Cohen's d to evaluate the size of the effect.

(c) Calculate the percentage of variance explained by the treatment of r², to measure effect size.