Understanding Basic Statistics 6th Edition by Charles Henry Brase,Corrinne Pellillo Brase

Exercise 113

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 decilitre of blood. In healthy adults, x is approximately normally distributed with mean = 38 and standard deviation = 12 (see reference in Problem 25). 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 an infection, anemia, or another type of illness.)