Question

Assume that the total cholesterol levels for adults are normally distributed with mean cholesterol level of 51.6 mg/dL and standard deviation

14.3 mg/dL. Find the probability that an individual will have a cholesterol level greater than 58 mg/dL.

Answer 1

Let the random variable denoting the cholestrol levels be X.

So, X ~ N(51.6, 14.3²)

So, the probability that an individual will have a cholestrol level greater than 58 =

P(X >58) = 1-P(X<58)

= 1 - P(Z < (58-51.6)/14.3)

= 1 - P( Z < 0.44755)

= 1 - 0.673

= 0.327.

So, the probability that an individual will have a cholestrol level of greater than 58 would be 0.327.