Question 1134221
a. P(4)=e^(-3)*3^4/4!=0.1680, Poisson formula
P(3)=e^(-3)*3^3/3!=0.2204
P(2)=0.2204
P(1)=e^-3*3=0.1494
P(0)=0.0498
d. So fewer than four has probability 0.64
c. More than four is 1-P(fewer than four, and includes four)=0.1920
P(5)=0.1008
P(6)=0.0504
So d is the sum of 0.1680+0.1008+0.0504=0.3192