The number of lost suitcases per week on an airline route is normally distributed with a mean of 15 and standard deviation of 3.5. The probability of losing less than 22 suitcases in a given week is calculated using the normal distribution and is equal to 0.9772.

1. an airline knows from experince that the distribution of the number of suitcaces that get lost each
week on a certain route is approximately normal with mean =15 and standard deviation = 3.5.
what is the probability that during a given week the airline will lose less than 22 suitcases?
Solution
= 15
= 3.5
Use a standard normal table to find the following probabilities:
P(x < 22) = P((x-)/ < (22 - 15)/3.5)
= P(z < 2) = .9772