Suppose you want to test the claim the paired sample data given below come from a population for which the mean difference is

.

x 77 76 68 83 85 80 50
y 83 93 81 86 69 77 62

Use a 0.05 significance level to find the following:

a. The mean value of the differences d for the paired sample data

b. The standard deviation of the differences d for the paired sample data.

c. The t-test statistic.

d. The positive critical value.