Question

A person’s blood glucose level and diabetesare closely related. Let x be a
random variable measured in milligrams of glucose per deciliter (1/10 of a liter)
of blood. After a 12-hour fast, the random variable x will have a distribution
that is approximately normal with mean μ=85 and standard deviation σ=25.
After 50 years of age, both the mean and the standard deviation tend to increase.
What is the probability that, for an adult (under 50 years old) after 12-hour
fast,
(a) x is more than 60?
(b) x is less than 110?
(c) x is between 60 and 110?
(d) x is greater than 140 (borderline diabetes starts at 140)?

Answer 1

Z = (score - mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the Z scores found.