Medical: Blood Protoplasm - Porphyrin is a pigment in blood protoplasm and other body fluids that is significant in body energy and storage. Let x be a random variable that represents the number of milligrams of porphyrin per deciliter of blood. In healthy adults x is approximately normally distributed with the mean μ= 38 and standard deviation σ = 12. What is the probability that:

a) x is less than 60

b) x is greater than 16

c) x is between 16 and 60

d) x is more than 60 (this may indicate infection, anemia, or another type of illness).