A paired difference experiment produced the following
results:
nd =38 x1 =92 x2 =95.5 xd =-3.5 sd
2
=21
a. Determine the values of z for which the null hypothesis,
m1 -m2 =0, would be rejected in favor of the alterna-tive hypothesis, m1 -m2 60. Use a=.10.
b. Conduct the paired difference test described in part a.
Draw the appropriate conclusions.
c. What assumptions are necessary so that the paired dif-ference test will be valid?
d. Find a 90% confidence interval for the mean difference
md.
e. Which of the two inferential procedures, the confidence
interval of part d or the test of hypothesis of part b, pro-vides more information about the differences between
the population means?