According to insurance records, a car with a certain protection system will be recovered 94% of the time. If 300 stolen cars are randomly selected, would it be unusual for 280 stolen cars to be recovered? In other words, is 280 more than 2 standard deviations above the mean? Note: Since np(1 - p) > 10 then we can assume the data approximates a normal distribution.

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.