Are you asking for someone to do this problem for you? It would help to get a meaningful answer, if you stated how comfortable you are with the subject matter, and in what areas you need assistance.
Manufacturer claims that its MX200 tires last for more than 5 years before they need to replaced. To test this claim at 95% confidence interval you took a sample of 12 customers who bought MX200 tires and found that the mean time of their tires was 6.25 years and a standard deviation of 1.5 years.
What is the critical Value (t-score) for this experiment
What is the test Statistics for this experiment
Is this a right,left,one,two tail hypothesis
Does it reject Fail to reject or there is no sufficient data to support the claim
Thank you