Keebler elf wants to know if cookie size changes how many cookies people eat. The elves have made their Fudge Stripe cookies in two sizes: the small cookies are 100 calories each and the large cookies are 250 calories each. To see if cookie size affects how many cookies people will eat, the elf randomly assigns 10 participants to one of two groups: the first group of 5 participants is given the small cookies and the second group of 5 participants is given the large cookies. The participants are told they can eat as many cookies as they want. The elf recorded the number of cookies each participant ate.

1. Why should the elf use an independent samples t-test? Thoroughly explain your answer.

2. State the elf's null and research hypotheses in words and symbols. 3. What degrees of freedom value should he use to determine the critical value for

this test? What is the critical value?

4. Calculate the appropriate t-test analysis (two-tailed, alpha = .05) given the following numbers:

Small cookie group data: M = 4.2, SD = 1.92 Large cookie group data: M = 1.3, SD = 0.44

5. Should the Keebler elf reject or fail to reject the null hypothesis based on the test statistic?

6. Now calculate the effect size.

7. Interpret the effect size according to the appropriate guidelines- is it trivial, small, medium, or large?

8. Write a paragraph explaining your results.