the government claims that the average age of texans is 38 years. blake hypothesizes that the average age of the population of texas is not equal to 38 years. blake records a sample mean equal to 41 and states the hypothesis as mu equals 38 vs mu not equal to 38 . select the best description for this type of test. a.) upper-tailed test b.) left-tailed test c.) right-tailed test d.) two-tailed test