About 10% of users do not close Windows properly.Suppose that Windows is installed in a public library that is used by random people in a random order:

(Hint: you can answer these questions by applying one of the distributions that you learned this week.)

1. On the average, how many users of this computer do not close Windows properly before someone does close it properly?
2. Suppose that in one day, 25 users make use of Windows.How many users are expected to have closed Windows properly?How many of them are expected to not close Windows properly? The number of computer shutdowns during any month has a Poisson distribution, averaging 0.25 shutdowns per month.
3. What is the probability of at least 3 computer shutdowns during the next year?
4. During the next year, what is the probability of at least 3 months (out of 12) with exactly 1 computer shutdown each?