Question

1. A researcher is interested in the effects of a new drug for memory enhancement (MOM) and finds 18 college student volunteers. She randomly assigns 6 students to each of 3 drug conditions (0 gmd, 10 gms or 20 gms) and then gives each a 15 item list to learn and immediately recall. The retention scores are presented below:

0 grams of MOM Retention Score

10 grams of MOM Retention Score

20 grams of MOM Retention Score

                                

8	10	10
6	7	8
7	8	7
5	6	9
10	11	15
9	11	13

1. Present the null and alternate hypotheses (2 pts)
2. Conduct an ANOVA on the data presenting your results in a Summary Table. (25 pts)
3. What is the critical value of F (2 pts)
4. What is your decision with respect to the null hypothesis (1pt)
5. What is the effect size for the independent variable drug dosage? (5 pts)

Answer 1

a.

b.

Anova: Single Factor
SUMMARY
Groups	Count	Sum	Average	Variance
0 grams of MOM	6	45	7.5	3.5
10 grams of MOM	6	53	8.833333	4.566667
20 grams of MOM	6	62	10.33333	9.466667
ANOVA
Source of Variation	SS	df	MS	F	P-value	F crit
Between Groups	24.11111	2	12.05556	2.062738	0.161656	3.68232
Within Groups	87.66667	15	5.844444
Total	111.7778	17

c. F0.05,2,17=Critical value=3.6823

d. Since F-value<Critical value so we fail to reject H0 at 5% level of significance.

e. Effect size=SSB/SST=24.11111/111.7778=0.22