Serum cholesterol is important risk factor for coronary disease suppose that serum cholesterol is approximately normally distributed with mean 214.7mg/dl and standard deviation 46.89mg/dl.

a. cholesterol levels in the top 19% are classified as high enough to warrant risk for heart disease what cholesterol level corresponds to this cut-off z score? and cholesterol level ? answer z score in 2 decimal places.

B. suppose cholesterol levels in the bottom 38% are classified normal. what cholesterol levels corresponds to a normal reading z score ? and cholesterol ?

c. between what two values do the middle 26% of cholesterol reading fail? z=+- ? and between ? and ?