SOLUTION: the telemarketing department of a company receives an average of four calls every minute. Find the probability that the department will receive exactly four calls at a randomly sel

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Question 1127379: the telemarketing department of a company receives an average of four calls every minute. Find the probability that the department will receive exactly four calls at a randomly selected time
a. exactly four calls at a randomly selected time
b. fewer than 2 calls at a randomly selected time
c. more than 9 calls at a randomly selected time

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
This is a Poisson distribution with parameter 4. It is Poisson, because number of calls is proportional to time, discrete, and could theoretically be infinite
From the table
for 4 it is 0.1954
that is e^(-4)*4^4/4!
For 2 or fewer it is 0.2381
Greater than 9, it is 0.0081