Q4 [7 pts] #16.8 Confidence level and margin of error. The NHANES survey data (text: example 16.1) on the body mass index (BMI) of 936 young men. The mean BMI in the sample was * = 27.2 . We treated these data as an SRS from a Normally distributed population with unknown mean and known standard deviation 0 = 11.6. (a) [6 pts] Give three confidence intervals for the mean BMI in this population, using 90%, 95%, and 99% confidence. Organize your steps by complete in the following table Confidence level Margin of error = z* o/vn Interval (Lower, upper) 90% 95% 99% (b) [1 pt] Look at your table obtained at (a), how does increasing the confidence level change the margin of error of a confidence interval when the sample size and population standard deviation remain the same