a.

Comparison of GPA for randomly chosen college juniors and seniors:

= 3.05, s1 = .20, n1 = 15, = 3.25, s2 = .30, n2 = 15, α = .025, left-tailed test.

b.

Comparison of average commute miles for randomly chosen students at two community colleges:

= 15, s1 = 5, n1 = 22, = 18, s2 = 7, n2 = 19, α = .05, two-tailed test.

c.

Comparison of credits at time of graduation for randomly chosen accounting and economics students:

= 139, s1 = 2.8, n1 = 12, = 137, s2 = 2.7, n2 = 17, α = .05, right-tailed test.

Do a two-sample test for equality of means assuming unequal variances.

For A,B, and C find:

d.f.

Standard Error

t-calc

p-value

t-crit