The probility of sucess on each trial of an experiment is .3 What's the probabilty of 5 successes in 8 trials

Question

these are the possible solutions....

.5734

.1361

.1239

.0467

or is it none of these?

Answer 1

5 successes and 3 failures in 8 trials is:

(0.3)^5 * (0.7)^3 * (8!)/(5! * (8-5)!)

That's the odds of 5 successful trials, times the odds of 3 unsuccessful trials, times the number of possible combinations for having 5 successful trials out of eight.

It is 0.04667544, which would match 0.0467 in your list.

Answer 2

The probability is:

P( 5 successes in 8 trials) = (8C5)*(.3^5)*(.7^3) = .0467

Answer 3

This is a typical binomial distribution.
P = C(8,5)(.3^5)(.7^3) = .04667544