Homework Week 4 Homework 40 pts 4315 Score o of 3 pts HW Sco

Homework Week 4 Homework 40 pts 4.3.15 Score: o of 3 pts HW Score: 81.25% (32.5 of 40 pts) 14 of 15 complete Find the indicated probabilities using the geometric distribution or Poisson distribution. Then determine if the events are unusual If convenient, use a Poisson probability table or technology to find the Assume the probablity that you wil make a sale on any given telephone callis 0.23 Find the probability that you(a)make yourfirst sale ontheff hcall, (b)make your sale on thefirst, second, or third call and (o do not make a sale on the first three cals E(a) P(make your first sale on the fifth cal) Round to three decimal places as needed

Solution

a) P (make your first sale on the fifth call) = 0.77^4 *0.23=0.081

b) P (make your sale on the first ,second or third call) = P(1) +P(2) + P(3) -P(1 and 2) -P(2 and 3) -P(1 and 3) + P(1 and 2 and 3)
                                                    = 0.23 +0.23 +0.23 -0.23^2-0.23^2-0.23^2 + 0.23^3
                                                    =0.543
c) P(do not make a sale on first 3 calls) = 0.77^3 = 0.456