# Assume that the monthly worldwide average number of airplaine crashes of commercial airlines is 2.2. ?

What is the probability that there will be

(a) more than 4 such accidents in the next month?

(b) less than 2 such accidents in the next 3 months?

(c) exactly 7 such accidents in the next 5 months?

### 1 Answer

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- rotchmLv 71 year ago
Assuming a Poisson distribution, since u did not specify which distribution you are using.

P(k) = a^k * e^(-a)/k! where a = the avg # events per time interval.

a) a=2.2. You want P(5) + P(6) + P(7) + ... = [left for you]. Hint: Use complement.

b) View it as a Poisson distrib with a = 3*2.2 = 6.6 events per 3 mo.

You want P(0) + P(1) + P(2).

c) View it as a = 5*2.2 events per 5 mo. You want P(7).

Show ur computations & answers & we can verify them for you.

Done

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