Cholesterol Levels For men aged between 18 and 24 years, serum cholesterol levels

(in mg 100 ml) have a mean of 178.1 and a standard deviation of 40.7 (based on data from the National Health Survey). Find the z score corresponding to a male, aged 18–24 years, who has a serum cholesterol level of 259.0 mg 100 ml. Is this level unusually high?