Question

An internal study by the Technology Services department at Lahey Electronics revealed company employees receive an average of 4.6 non-work-related e-mails per hour. Assume the arrival of these e-mails is approximated by the Poisson distribution.

What is the probability Linda Lahey, company president, received exactly 1 non-work-related e-mail between 4 P.M. and 5 P.M. yesterday? (Round your probability to 4 decimal places.)

What is the probability she received 8 or more non-work-related e-mails during the same period? (Round your probability to 4 decimal places.)

What is the probability she received four or less non-work-related e-mails during the period? (Round your probability to 4 decimal places.)

Answer 1

When we want to predict the probability of certain events in a fixed interval of time, poison distribution follows. The probability mass function of poison distribution is,

1)

2)

x	Pr
0	0.010052
1	0.046238
2	0.106348
3	0.163068
4	0.187528
5	0.172526
6	0.13227
7	0.08692
Pr(X<=7)	0.904949
Pr(X>=8)	0.095051

3)

x	Pr
0	0.010052
1	0.046238
2	0.106348
3	0.163068
4	0.187528
Pr(X<=4)	0.513234