please be descriptive

. It is known that the tar content of a certain kind of cigarette has a mean of 15 mg per cigarette and standard deviation cr = 3 mg. A manufacturer claims that the},r have reduced the tar contents in their cigarettes. To test this claim, 70 cigarettes are randomly selected from this company's products to test to tar contents. (a) {3pts) Formulate the null and alternative hypotheses. (b) {4pts} Determine the test statistics and the rejection region at signicance level or = 0.05. (c) {3pts) If X = 14.6, what does the test conclude? (d) {5pts) Calculate the pvalue