Experts suggest high serum cholesterol levels to be associated with raised incidence of coronary heart disease. Assume that the natural logarithm of cholesterol levels for males in the given age bracket is normally distributed with mean of 5.35 and a standard deviation of .12.
(a) What percentage of the males in this age bracket could be expected to have serum cholesterol level greater than 250 mg/ml, the upper limit of the clinical normal range? %
(b) What percentage of the males could be expected to have serum cholesterol levels in the clinical normal range of 150-250 mg/ml? %
(c) If levels above 300 mg/ml are considered extremely risky, what percentage of the adult males in this age bracket could be expected to exceed 300? %