Q:

A tire company has developed a new type of steel-belted radial tire. Extensive testing indicates the population of mileages obtained by all tires of this new type is normally distributed with a mean of 40,000 miles and a standard deviation of 4,000 miles. The company wishes to offer a guarantee providing a discount on a new set of tires if the original tires purchased qualify the guarantee mileage. What should the guaranteed mileage be if the tire company desires that no more than 2 percent of the tires will fail to meet the guaranteed mileage? (2 points)

Accepted Solution

A:
Answer:The guaranteed mileage should be 31800 miles.Step-by-step explanation:Consider the provided information.It is given that the normally distributed with a mean of 40,000 miles and a standard deviation of 4,000 miles. Also the company desires that no more than 2 percent of the tires will fail to meet the guaranteed mileage.That means the p < 0.02Now with the help of the table the respective Z-score value of p < 0.02 is Β -2.05 From the provided information mean and standard deviation is given as [tex]\mu = 40,000\ \text{and}\ \sigma = 4000[/tex]Now use the formula: [tex]z=\frac{x-\mu}{\sigma}[/tex]Substitute the respective values in the above formula.[tex]-2.05=\frac{x-40000}{4000}[/tex][tex]-8200=x-40000[/tex][tex]-8200+40000=x[/tex][tex]31800=x[/tex]Hence, the guaranteed mileage should be 31800 miles.