A poll is given, showing 70% are in favor of a new building project.

Question

If 7 people are chosen at random, what is the probability that exactly 5 of them favor the new building project?

Answer 1

Pr(exactly5)=.7^5 * .3^2 * C(7,5)

C(7,5)=7!/5!*2!=21
Pr= 21*.7^5*.3^2=.318