a. A college admissions director wishes to estimate the mean age of all students currently enrolled. In a random sample of 30 students the mean age is found to be 22.9 years. From past studies the standard deviation of all students is known to be 1.5 and the population is normally distributed. Construct a 90% confidence interval of the population mean age,()

b. A cheese processing company wants to estimate the mean cholesterol content of the cheese. The estimate is within 0.5 milligrams of the population mean.Determine the minimum required sample size to construct a 95% confidence interval for the population mean.Assume the standard deviation is 2.8 milligrams.