The data for a random sample of six paired observations are shown in the next table.

a. Calculate the difference between each pair of observations by subtracting observation 2 from observation 1. Use the differences to calculate xd and sd 2.

b. If m1 and m2 are the means of populations 1 and 2, respectively, express md in terms of m1 and m2. Pair Sample from Population 1 (Observation 1) Sample from Population 2 (Observation 2) 1 7 4 2 3 1 3 9 7 4 6 2 5 4 4 6 8 7

c. Form a 95% confidence interval for md.

d. Test the null hypothesis H0: md = 0 against the alternative hypothesis Ha: md ≠ 0. Use a = .05.