Question 1171055
This is a binomial probability problem with the probability of "success"
equal to 0.7. The probability of x successes in n trials is given by:
P(x) = C(n,x)p^x(1-p)^(n-x), where C(n,x) is the number of combinations
(n things taken x at a time)
Thus P(3) = C(7,3)*0.7^3*0.3^4 = 0.0972