Please help thank you

An auto maker is interested in information about how long transmissions last. A sample of transmissions are run constantly and the number of miles before the transmission fails is recorded. The auto maker claims that the transmissions can run constantly for over 150,000 miles before failure. The results of the sample are given below. Miles (1000s of miles) Mean 151.2 Variance 17.22 Observations 44 Hypothesized Mean 150 df 43 t Stat 1.889 Ex: 1.234 + P(T