# Probability Question - POLITICS?

1. Oct 30, 2008

### apoechma

Probability Question - POLITICS?! :)

In a recent survey 480 out of 600 Canadians polled stated that they were dissatisfied with politicians. OF the remainging 120 who were olled, 75% were satisfied with politicians, and 25% had no opinion. Assuming that these findings can be generalized to all Canadians, then:

a) In a radon sample of 4 Canadieans what is the probability that no more than 1 would be satisfied with politicians?

b) If two random and independent samples of Canadians were taken, one consisting of 20 people and the other of 25 people, what is the probability either that more than 18 of the sample of 20 or that between 19 and 23 of the sample of 25 would state a definite opinion for or against about politicians?

For a:
I KNOW that 480/600 = .8 dissatisfied
90/600 = .15 satisfied (75% of 120)
30/600 = .05 no opinion ( 25% of 120)

So for 4 Canadians _ _ _ _ I worked it as exactly 1 Canadian would be satisfied then PLUS NO Canadians would be satisfied. HOWEVER I do not know how to do it! PLEASE HELP!!!!! Like S_ _ _ >>? Whats the other 3 options, can they be disastisfied and no opinion?? COuld someone PLEASE work out problem for me and I will understand once i see it!?!?!?

THANK U SO MUCH u have NO IDEA how Much I appreciate this!!!!

2. Oct 30, 2008

### HallsofIvy

Staff Emeritus
Re: Probability Question - POLITICS?! :)

You just said that .8 of your sample were dissatisfied. If that holds true for all Canadians (which is assumed here) then .8 of any sample of 4 people should be dissatisfied. What is (.8)(4)? What integer does that round to?

You have .15 satisfied so what is (.15)(4)? What integer does that round to?
What is (.05)(4)? What integer does that round to?