The local police department must write, on average, 5 tickets a day to keep department revenues at budgeted levels. Suppose the number of tickets written per day follows a Poisson distribution with a mean of 6.5 tickets per day. Interpret the value of the mean.

a. The number of tickets that is written most often is 6.5 tickets per day.

b. If we sampled all days, the arithmetic average or expected number of tickets written would be 6.5 tickets per day.

c. Half of the days have less than 6.5 tickets written and half of the days have more than 6.5 tickets written.

d. The mean has no interpretation since 0.5 ticket can never be written.