An exponential distribution with a parameter, λ, is given by
[tex]F_X(x)=1-e^{-\lambda x}, \ \ \ x\geq2[/tex]
Given that the flights arrivals obey an exponential distribution with a mean of 4.5 minutes between flights.
The probability that two successive arrivals occur within 2.0 minutes of each other is given by
[tex]P(X\leq2)=F_X(2) \\ \\ =1-e^{-4.5\times2}=1-e^{-9}[/tex]
