BMI (body mass index) is obtained as weight (in kg) divided by the square of height (in m2). Adults with BMI over 25 are considered overweight. A trainer at health club measured the BMI of people who registered for his program this week. Here are the observations: 29.4, 24.2, 25.6, 23.6, 23.0, 22.4. Assume that the population is normal with variance 6.4 a. Construct a 95% confidence interval for the mean BMI. b. What would be the required sample size to estimate the mean BMI to be within 0.1 kg/m2 with 95% confidence