Note: Please show the work in detail for all questions.

1. Fifteen students were given different drug treatments before revising for their exams. They were randomly split into three groups where some were given a memory drug, some a placebo drug, and some no treatment. The exam scores (%) are shown below for the three different groups.

Memory Drug (Xbarmemory)	Placebo (Xbarplacebo)	No Treatment (Xbarcontrol)
70	37	3
77	43	10
83	50	17
90	57	23
97	63	30

a. What type of design is this study?

b. What is the df_treat?

c. What is the df_error?

d. Calculate the F test value, state the critical value, and provide an interpretation for the null hypothesis. MS_treat = 557.78; MS_error = 111.20; alpha = .01

2. In this study, four children were tested three times, at ages 10,11, and 12. At each age, they worked a set of 25 logic problems. The scores below represent the percentage of problems they got correct.

Participant	Age 10 (XA)	Age 11(XB)	Age 12 (XC)
1	4	8	40
2	8	12	36
3	12	24	36
4	16	20	48
Xbar	10	16	40

a. What type of design is this study?

b. State the df_treat , df_error, the critical F- value, and provide an interpretation of the null hypothesis given the information above and the following: alpha = .05, F- value (calculated) = 4.92.

c. Calculate the HSD test value for the comparison of 10 to 11 years old, and 10 to 12 years old, state the critical value, and provide an interpretation for the null hypothesis of significantly different comparisons only. Round to 2 decimals S_x = 2.38; alpha = .05.