7. the manufacturer of a new fiberglass tire claims that its average life will be at least 40,000 miles. to verify this claim, sample of 78 tires are tested. sample mean was 37.8 (in 1000 miles). assuming the measurements were random sample from a normal distribution with standard deviation of 12.5, using 95% one-sided confidence interval, choose the best answer from choices (a)-(e) below to the following question. can this data be taken as a statistical evidence that the true mean life of tires is less than 40 (in 1000 miles)?