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In a small candy shop in a small town, the number of customers in a typical day

ID: 2957884 • Letter: I

Question

In a small candy shop in a small town, the number of customers in a typical day has a Poisson distribution with an expected value (mean, average) of one. The probabilities for the distribution are:

0 customers : 0.3679
1 customer: 0.3679
2: 0.1839
3: 0.0613
4: 0.0153
5: 0.0031
6: 0.0005
>7: 0.0001
A. The shop owner calls a day successful if there are at least two customers. What is the probability of a successful day?
B. The shop owner is satisfied with a week’s business if it has at least three successful days. Write a formula, with numbers in it, for the probability that the shop owner will be satisfied with a typical week. If the formula is complicated, you don’t need to reduce it to a single number.

Explanation / Answer

A. 1-[0.3679+0.3679] = 0.2642 B. Assuming the shop is open 7 days a week: 1-binomcdf(7,0.2642,2) = 0.2736