The Number of Parking Tickets Issued in Grand Rapids on Any

Essay

The number of parking tickets issued in Grand Rapids on any given weekday has a Poisson distribution with parameter $\hat\lambda = 50$ What is the approximate probability that
a. Between 40 and 70 tickets are given out on a particular day? (Hint: When $\hat\lambda$
is large, a Poisson random variable has approximately a normal distribution.)
b. The total number of tickets given out during a 5-day week is between 215 and 265?