the lytton rubber company wishes set a minimum mileage guarantee on its new Mx 100 tire. Tests reveal the mean mileage is 67,900 with the standard deviation of 2,050 miles and that the deviation follows normal distribution. They want to set the minimum mileage guarantee so that no more than 4 percent of tires will have to be replaced. Due to the costly nature of the test the company decided to take a sample of 200 tires.

Question

A.What average guaranteed mileage should Lytton announce ?
B. Assume that if tires mileage is below 67,500 the company is obliged to return back the used tire ? What is the probability of returning back? How many tires retune buck out of the sample ?
C. Assume that the company wants to know the 95% confidence interval for the average mileage of its tires. What would be the interval?
D. If the company asks you to state the appropriate sample size to determine 99% confidence interval of the average mileage with the error not more than 1000 miles what would be your recommendation ?

Answer 1

Statistics

Answer 2

first question answer

Answer 3

statistics

Answer 4

Lytton rubber company

Answer 5

566385

Answer 6

A. Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability (.04) and its Z score. Insert Z into above equation and solve for score.