Suppose we randomly select two independent samples from populations having means 1, and 2. If 1, =

Suppose we randomly select two independent samples from populations having means µ1, and µ2. If 1, = 25, 2 = 20, σ1, = 3, σ2 = 4, n1, = 100 and n2 = 100:
a. Calculate a 95 percent confidence interval for µ1, - µ2. Can we be 95 percent confident that µ1, is greater than µ2? Explain.
b. Test the null hypothesis H0: µ1 - µ2 = 0 versus Ha: µ1 - µ2 > 0 by setting a = .05. What do you conclude about how µ1, compares to µ2?
c. Find the p-value for testing H0: µ1 - µ2 = 4 versus Ha: µ1 - µ2 > 4. Use the p-value to test these hypotheses by setting a equal to .10, .05, .01, and .001.