Question: It is known that 20% of ticketed passengers on Southwest Airlines flights end up being no-shows for their flights. A typical Southwest flight has 138 seats.

A. What is the expected number of no-shows on any given flight, assuming 138 tickets were sold? In other words, calculate E(X) for this situation.

B. Now calculate the standard deviation for this distribution, \(\sqrt{np\left( 1-p \right)}\)

C. We know that anything outside of two standard deviations is unusual. If 14 of the passengers (out of 138) were no-shows, would this be considered unusual, or does this seem reasonable to happen just by chance?