The postsurgery survival time of a breast cancer patient is normally distributed with a mean of eight years and a standard deviation of 1.5 years. Find the probabilities that a woman with breast cancer will survive after her surgery: (a) between five and seven years, (b) more than 11 years, (c) less than six years.

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.