probability and statistics

Question

Find the probability of having 2,3, or 4 successes in five trials of a binomial experiment in which the probability of success is 40%. Round to the nearest tenth of a percent.

Answer 1

Let p = .4 and q = .6

The probability you want is ₅C₂p²q³ + ₅C₃p³q² + ₅C₄p⁴q

The numerical values are simply a nuisance to calculate...and BTW the terms with C in them are the binomial coefficients.