According to an airline a particular flight is on time 75 of

According to an airline, a particular flight is on time 75% of the time. Suppose 70 flights are randomly selected. Compute the mean and standard deviation of the random variable X, the number of on-time flights in 70 trials of the probability experiment.

Solution

a)
Mean ( np ) = 70*0.75 = 52.5
b)
Standard Deviation ( npq )= 70*0.75*0.25 = 3.6228 ~ 3.62