1. Consider a one-way ANOVA with five samples that are all the same size, but whose standard deviations are different: s1 = 10, s2 = 15, s3 = 12, s4 = 11, and s5 = 10.

a. Can you calculate MSW from the information given?

b. If so, what would be the value for MSW?

2. A psychologist is studying the effects of various drugs on the speed of mental arithmetic. In an exploratory study, 32 subjects are divided equally into four drug conditions, and each subject solves as many problems as he or she can in 10 minutes. The mean number of problems solved follows for each drug group, along with the standard deviations:

	Marijuana	Amphetamine	Valium	Alcohol
X	7	8	5	4
s	3.25	3.95	3.16	2.07

a. Calculate the F ratio.

b. Find the critical F( = .05).

c. What can you conclude with respect to the null hypothesis?