Assume that on a week day one telephone number out of every ten being called is busy.If 6 randomly selected numbers are called what is the probability that at least three of them will be busy?

Answer 1

use binomial distribution.
I have to go clean seagull poop and snow off high school sailing floats, will check back this afternoon to see if you got it.

Answer 2

looks like Damon is still cleaning seagull poop ....

prob(busy) = 1/10
prob(not busy) = 9/10

prob(at least 3 of 6 are busy)
= C(6,3)(1/10)^3 (9/10^3) + C(6,4) (1/10)^4 (9/10)^2 + ... + C(6,6) (1/10)^6

I will let you do the button-pushing

Answer 3

Thank you Reiny. Indeed we had quite a time getting ready for the first day of sailing practice.