7 please

7. High blood cholesterol is a major risk factor for coronary heart disease and stroke. The level of cholesterol in blood is measured in milligrams per deciliter (mg/dL). According to the WHO, less than 200 mg/dL is a desirable level, 200 to 239 mg/dL is borderline high, and above 240 mg/dL is a high risk level. In a certain country, adult blood cholesterol levels are normally distributed with an average of 184 mg/dL and a standard deviation of 22 mg/dL. a) What percentage of the population is borderline high? [2 marks] b) What percentage is high risk? [2 marks] c) Estimate the interquartile range of the cholesterol levels in this country. [3 marks]