The superintendent of a large school district, having once had a course in probability and statistics, believes that the number of teachers absent on any given day has a Poisson distribution with parameter m. Use the accompanying data on absences for 50 days to obtain a large-sample CI for m.

[Hint: The mean and variance of a Poisson variable both equal m, so Z 5 X 2 m 1m/n 2/3 has approximately a standard normal distribution. Now proceed as in the derivation of the interval for p by making a probability statement (with probability ) and solving the resulting inequalities for — see the argument just after

(7.10).]

Number of absences 0 1 2 3 4 5 6 7 8 9 10 Frequency 1 4 8 10 8 7 5 3 2 1 1