Objective:

sample.:Test a claim about a population mean and standard deviation based on a

Project: Use a 0.05 level of significance, to identify which automobile tire manufacturer should be awarded the Illinois State Police tire contract. The Illinois State Police Department is interested in tires for its squad cars.

These tires must satisfy the specification that the average (Mean) life of the tire must be at least 80,000 miles and the standard deviation must be at most 200 miles.

Four different tire makers, Tirel, Tire2, Tire3 ,and Tire4 sent the automaker several tires to be tested. (The identities of the tire manufacturers remain anonymous to guarantee a nonprejudicial test.) The tires were placed on the drive wheels of various squad cars and driven until the tires were worn down.

The following data shows the mileage the tires traveled before they had to be

replaced. and Tire4 sent the automaker