"D" size batteries produced by MNM Corporation have had a life expectancy of 86 hours. Because of an improved production process, it is believed that there has been an increase in the life expectancy of its " D" size batteries. A sample of 25 batteries showed an average life of 88.5 hours. Assume from past information that it is known that the standard deviation of the population is 7hours
a. formulate the hypotheses for this problem
b. compute the test statistic, and at 95% confidence, test the hypotheses
c. What is the p-value associated with the sample results? What is your conclusion based on the p-value?