A car salesman sells on average 3 cars per week Find the pro

A car salesman sells on average 3 cars per week. Find the probability, that in a given week, the car salesman will sell 2 or more, but less than 5 cars. Use Appendix A.2. Question 14 of 14 What is the variance for the numbers of cars sold by the salesman in question 13? Round the answer to the nearest one significant figure.

Solution

Q13

Poisson distribution used

Mean =3

Poisson with mean = 3

x P( X = x )

0    0.049787

1    0.149361

2    0.224042

3    0.224042

4    0.168031

5    0.100819

P( 2<= x < 5) = P( x=2)+p(x=3)+p( x=4)

= 0.224042+ 0.224042+ 0.168031

= 0.61612

Q14

In poisson, mean = variance

Variance =3