CSSA 2004 Trails Question (1 Viewer)

[ressul]

In a certain street, 40% of the households have at least 2 cars. If 4 households are chosen at random, find the peobability that:
b.at most of these households have at least 2 cars.
What does this question mean and how to do it?

 

[Rorix]

its a binomial probability question

 

[cranberries]

you do it like:

P(At least 2 cars)= 0.4 = p
P(NOT at least 2 cars) =0.6= q

(p+q)^4 = whatever the binomial expansion is

i would write it but i'm not very good with typing maths stuff

and then you find the one with the p's and q's that you want and sub in the 0.4's and 0.6's !

 

[Rorix]

In a certain street, 40% of the households have at least 2 cars. If 4 households are chosen at random, find the peobability that:
b.at most of these households have at least 2 cars.
What does this question mean and how to do it?

by the way, your question is missing a number. It should be "at most X of these" where x is a number.

hence it cant be answered.

it will have something to do with summing 4Cn (0.4)^n (0.6)^(4-n) thou