High levels of cholesterol in the blood increase the risk of heart disease. For 14-year-old boys, the distribution of blood cholesterol is approximately Normal with mean ? = 170 milligrams of cholesterol per deciliter of blood (mg/dl) and standard deviation ? = 30 mg/dl.
What is the median of the distribution of blood cholesterol for 14-year-old boys?
A) cannot be determined without actual data
B) 170 + 30
C) 170
D) 30