Question

1. The Rogers Bicycle & Gun Company sells a light, new road tire that they advertise to go over 5,000 miles before it must be replaced. Several of the company’s customers have complained that the new tire does not actually make it to 5,000 miles. The company decided to test the tires. They tested a sample of 25 tires and found the average tire life to be 4,300 miles with a standard deviation of 500 miles. It will cost the company money if they have to change their advertisements, but they want to keep their customers’ trust. They have decided to restate their advertised claim only if there is significant evidence (α = 0.05) to infer that the tire life is less than 4,500 miles.

   After calculating the correct test statistic, which is the best decision for your result?

   		Fail to reject the null hypothesis; there is sufficient evidence to conclude that the customers’ claims are unfounded
   		Reject the null hypothesis; there is not sufficient evidence for the bike company to change the advertised life of the new tire
   		Fail to reject the null hypothesis; there is not sufficient evidence for the bike company to change the advertised life of the new tire
   		Reject the null hypothesis; there is sufficient evidence for the bike company to change the advertised life of the new tire

Answer 1

here we will conduct hypothesis t test for mean since the population standard deviation of tire life is not given.

option D is right Reject the null hypothesis; there is sufficient evidence for the bike company to change the advertised life of the new tire