In order to compare the means of two populations, independentrandom samples of 400 observations are selected from eachpopulation, with the results found in the table to the right.Complete parts a through e.
Sample 1
x1 = 5,265
s1 = 157
Sample 2
x2 = 5,232
s2 = 203
a. use a 95% confidence interval to estimate the differencebetween the population means (u1 - u2). Interpret the confidenceinterval.
b. test the null hypothesis H0: (u1 - u2) = 0 versus thealternative hypothesis Ha:(u1 - u2) =/ 0. Give the significancelevel of the test, and interpret the result.
c. Suppose the test in part b was conducted with the alternativehypothsis Ha:(u1 - u2) > 0. How would your answer to part bchange?
d. test the null hypothesis H0:(u1 - u2) = 30 versus Ha:(u1 -u2) =/ 30. Give the significance level, and interpret the result.Compare your answer to the test conducted in part b.
e. What assumptions are neccessary to ensure the validity of theinferential procedures applied in parts a - d?