Suppose that the average height of men in the United States is approximately normally distributed with a mean of approximately 70 inches and a standard deviation of approximately 4 inches. (a) What fraction of men’s heights are less than 68 inches? (b) What fraction of men’s heights are greater than 73 inches? (c) What fraction of men’s heights are between 68 and 73 inches?

Features Features Normal distribution is characterized by two parameters, mean (µ) and standard deviation (σ). When graphed, the mean represents the center of the bell curve and the graph is perfectly symmetric about the center. The mean, median, and mode are all equal for a normal distribution. The standard deviation measures the data's spread from the center. The higher the standard deviation, the more the data is spread out and the flatter the bell curve looks. Variance is another commonly used measure of the spread of the distribution and is equal to the square of the standard deviation.