Under the null hypothesis H0 that traffic is typical, the number of call attempts in a 1-second interval (during rush hour) at a mobile telephone switch is a Poisson random variable N with E[N] = 2.5. Over a T-second period, the measured call rate is M = (N1 + ... + NT)/T, where N1,..., NT are iid Poisson random variables identical to N. However, whenever there is unusually heavy traffic (resulting from an accident or bad weather or some other event), the measured call rate M is higher than usual. Based on the observation M, design a significance test to reject the null hypothesis Ho that traffic is typical at a significance level α = 0.05. Justify your choice of the rejection region R.