A tire manufacturer believes that the tread life of its snow tires can be described by a Normal model with a mean of 25,000 miles and a standard deviation of 2300 miles. Complete parts a through e...

part C DE

Extracted text: A tire manufacturer believes that the tread life of its snow tires can be described by a Normal model with a mean of 25,000 miles and a standard deviation of 2300 miles. Complete parts a through e below. a) If you buy a set of these tires, would it be reasonable for you to hope that they'll last 31,000 miles? Explain. About % of tires are expected to have a tread life greater than 31,000 miles. It be reasonable to hope that your tires lasted this long. (Round to one decimal place as needed.) b) Approximately what fraction of these tires can be expected to last less than 22,000 miles? About % of these tires can be expected to last less than 22,000 miles. (Round to one decimal place as needed.) c) Approximately what fraction of these tires can be expected to last between 22,000 and 28,000 miles? About % of these tires can be expected to last between 22,000 and 28,000 miles. (Round to one decimal place as needed.) d) Estimate the interquartile range (IQR) for these data. The IQR is miles. (Round to the nearest mile as needed.) e) In planning a marketing 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 of a risk. If the dealer is willing to give refunds to no more than 1 of every 20 customers, for what mileage can he guarantee these tires to last? The tire dealer can guarantee these tires last at least (Round to the nearest mile as needed.) miles.