A tire manufacturer has been producing tires with an average life expectancy of 27,000 miles. Now the company is advertising that its new tires' life expectancy hasincreased. In order to test the legitimacy of the advertising campaign, an independent testing agency tested a sample of 8 of their tires and has provided the following data.

Longevity

(In Thousands of Miles)

28.0

26.5

27.2

26.0

28.3

26.4

29.1

25.0

a.	Determine the mean and the standard deviation.
b.	Formulate the correct hypotheses to determine whether or not the tire company is using legitimate adversiting.
c.	At the .10 level of significance using thecritical value approach, test to determine whether or not the tire company is using legitimate advertising. Assume the population is normally distributed.
d.	Repeat the test using thep-value approach.