Question

Part 3: The Normal Distribution

A tire manufacturer believes that the tread life of their tires can be described by a normal distribution with a mean of 32,000 miles and a standard deviation of 2,500 miles.  

Use StatCrunch. Copy and paste all StatCruch output used.

1. What is the probability that one of these tires lasts longer than 35,000 miles? (6 points)

2. What is the probability that one of these tires lasts between 20,000 and 40,000 miles?
   (6 points)

3. What is the probability that one of these tires lasts no more than 32,500 miles? (6 points)

4. In planning a market strategy, a local tire dealer wants to offer a refund to any customer whose tires fail to last a certain number of miles. However, the dealer does not want to take too big a risk. If the dealer is willing to give refunds to no more than 3% of his customers, how many miles can he guarantee these tires to last? (8 points)

Answer 1