The time (Y) it takes your professor to drive home each night is normally distributed with mean 15 minutes and standard deviation 2 minutes. Find the following probabilities. Graph the normal distribution and standard normal distributions, and show (shade) the areas that represents the probability you are calculating. a. P( 11 < Y < 19) = b. P (Y ≤ 18) = c. P(Y > 25) =

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.