Originally Posted by

**djmccabie** Been a while since i dealt with poisson distribution any help is appreciated =]

X~Po (5)

Find probability that

i) exactly 6 are sold in a randomly chosen week

ii) exactly 6 are sold in each of 3 randomly chosen weeks

iii) exactly 18 are sold in a randomly chosen 3 week period

ok for i I use the formula (e^-λ8λ^X) / X!

which gives me (e^-5 8 5^6) / 6!

= 0.1462 (4 d.p.)

now for part ii is it the above answer cubed?? giving 3.1264 x10^-3

really cant remember how to do part iii