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?
- 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.