The sales of a supermarket had an average of $14,000 per day. The store introduced several promotion campaigns in order to increase sales. To determine whether or not the promotion campaigns have been effective in increasing sales, a sample of 144 days of sales was selected. It was found that the average was $16,000 per day. From past information, it is known that the standard deviation of the population is $9,600. The null hypothesis is to be tested at 95% confidence. a. Formulate the null and alternative hypotheses.
b. What is the z value of the test statistic?
c. What is the critical value?
d. What is the p-value for your hypothesis test?
e. What is your conclusion? How do you get this conclusion