Question

34​% of a certain​ country's voters think that it is too easy to vote in their country. You randomly select 12 likely voters. Find the probability that the number of likely voters who think that it is too easy to vote is​ (a) exactly​ three, (b) at least​ four, (c) less than eight.

Answer 1

(a)

Binomial Distribution

n = 12

p = 0.34

q = 1 - p = 0.66

(b)

P(X4) = 1- [P(x=0) + P(X=1) + P(X=2) + P(X=3)]

So,

P(X4) = 1 - 0.3742

= 0.6258

So,

Answer is:

0.6258

(c)

P(X<8) = P(X=0) + P(X=1)+P(X=2)+P(X=3)+P(X=4)+P(X=5)+P(X=6)+P(X=7)

So,\P(X<8) = 0.9787

So,

Answer is:

0.9787