Assume cholestrerol levels are approximately normally distributed with a mean of 189.1 mg/dL and a standard deviation of 37.8 mg/dL.Using Excel for calculations, answer the following:

a)i.Calculate the z-score for a person whose cholesterol is 245.mg/dL

ii.Calculate the z-score for a person whose cholesterol is 162.9 mg/dL.

b)If x represents a cholesterol level, findP(x > 220).

c) Calculate P(175 < x < 230) and write a sentence for the interpretation of this value.

d)Persons with the highest 15% of cholesterol levels are referred to their doctor for further testing.Determine the cholesterol level that would warrant further testing.