Question

Hypothesis Tests

Sample statistic	Competitor A	Competitor B	Competitor C
Mean	54,028.400	50,407.686	63,478.371
St. Dev.	14,803.261	5,466.700	19,547.485
N	35	35	35

Using the sample statistics above, test each competitor's claim about their tires' tread life at the 5% significance level. Recall the following from the project.

Suppose you work at a large tire distribution center. The tires’ average tread life has been 50,000 miles with a standard deviation of 5,000 miles. At the end of the year, the company can reevaluate their supply contract. There are four supply options for the next contract: the current supplier or one of three competitors.

H0 : μ=μ0
HA: μ≠μ0

A). What is the critical t-score for our hypothesis tests at the 5% significance level? Using the table, you will have four (4) decimal places. (Remember, we are conducting a two-tailed test.)?

B). Hypothesis Tests: Competitor A

What is the t-test statistic for Competitor A? Remember, Competitor A claims a tread life of 52,000 miles?

C). Hypothesis Tests: Competitor B

What is the t-test statistic for Competitor B? Remember, Competitor B claims a tread life of 50,000 miles?

D). Hypothesis Tests: Competitor C

What is the t-test statistic for Competitor C? Remember, Competitor C claims a tread life of 60,000 miles?

Answer 1