2 The number of cars arriving per minute to queue at a drive-through fast-food restaurant is modelled by the random variable \(X\). The standard deviation of \(X\) is 0.6 . You should assume that arrivals are random and independent and occur at a constant average rate.
- Find the mean of \(X\).
- Calculate \(\mathrm { P } ( X = 1 )\).
- Calculate \(\mathrm { P } ( X > 1 )\).
- Find the probability that fewer than 5 cars arrive in a randomly chosen 20 -minute period.