Answer: (a) 0.8641
(b) 0.1359
Explanation:
Given : The monthly worldwide average number of airplane crashes of commercial airlines
![\lambda= 3.5](https://img.qammunity.org/2020/formulas/mathematics/college/m6wqecp670jdfdj6ord5rik6gs3i0xuizz.png)
We use the Poisson distribution for the given situation.
The Poisson distribution formula for probability is given by :-
![P(X=x)=(e^(-\lambda)\lambda^x)/(x!)](https://img.qammunity.org/2020/formulas/mathematics/college/ujbupmporiyem3i0tedi4cwo5zl88mmb6a.png)
a) The probability that there will be at least 2 such accidents in the next month is given by :-
![P(X\geq2)=1-(P(X=1)+P(X=0))\\\\=1-((e^(-3.5)(3.5)^0)/(0!)+(e^(-3.5)(3.5)^1)/(1!))\\\\=1-(0.1358882254)=0.8641117746\approx0.8641](https://img.qammunity.org/2020/formulas/mathematics/college/2p1f7rpqun7y5b7ckadj1zwr2sqcpa9t4l.png)
b) The probability that there will be at most 1 accident in the next month is given by :-
![P(X\leq1)=(P(X=1)+P(X=0))\\\\=(e^(-3.5)(3.5)^0)/(0!)+(e^(-3.5)(3.5)^1)/(1!)\\\\=0.1358882254\approx0.1359](https://img.qammunity.org/2020/formulas/mathematics/college/asdwps1bx2jqenzfs9ke4vrzdipvn97rz1.png)