statistics
posted by peter .
(a)Comparison of GPA for randomly chosen college juniors and seniors:
xbar= 3.05, s1 = .20, n1 = 15, xbar2= 3.25, s2 = .30, n2 = 15, รก = .025, lefttailed test.
calculate
d.f. ____________
Standard error ____________
tcalculated ____________
pvalue ____________
tcritical ____________

This looks like an independent groups ttest.
Here are a few hints:
1. d.f. for an independent groups ttest is this: n1 + n2  2
2. Use the denominator of the appropriate ttest as the standard error of the difference between the two means.
3. Use the appropriate ttest to calculate the ttest statistic.
4. Pvalue is the actual level of the ttest statistic (found using a ttable).
5. Tcritical can be found using a ttable with the appropriate degrees of freedom for a onetailed test.
I hope this will get you started.