Two sets of elementary school children were taught to read by using different methods, 50 by

each method. At the conclusion of the instructional period, a reading test yielded the results

y1=74, y2=71, s1=9, s2=10.

Consider the problem of testing whether there is a difference in the population means between the two groups. Which of the following is the appropriate form of the p-value?

a. P(X>c)+P(X0

b. P(X>c) where X is t distributed and c>0

c. P(X0

d. P(X0

e. P(X>c)+P(X0

f. P(X>c) where X is normally distributed and c>0