4.42 You are investigating the punctuality of the airlines in Asia. Your survey tells you that, out of 15 airlines, 80%

of them are likely to be late at least once a month. Assume the punctuality random variable follows a binomial distribution. Determine the following.

a. Which assumptions do you need to make in order to be correct in considering a binomial distribution for your variable?

b. How many airlines will be late in one month?

c. What is the standard deviation of this random variable (i.e., the risk of being late)?

d. What is the probability that they all will be late?