An auto magazine wants to review the tread mileage wear of two sports tires. We will compare the average tread wear before replacement between Micheline and Pirelli. As we don’t know which brand as a...

An auto magazine wants to review the tread mileage wear of two sports tires. We will compare the average tread wear before replacement between Micheline and Pirelli. As we don’t know which brand as a higher average treadwear we will use a two-tailed test. The magazine randomly samples 44 Micheline tires and they had an average treadwear of 20,000 miles before replacement, with a standard deviation of 2,000 miles. There was a random sample of 48 Pirelli tires. The average tread wear of the 48 Pirelli tires was 21,000 miles with a standard deviation of 2,000 miles. Define the first population as the Micheline tires and the second population as the Pirelli tires.  Using a 5% significance level determine if the brand competitors do not have an average equal tread wear.

Give the hypothesis, the reject region, test statistic, and conclusion.