Question

Suppose your experiment consists of repeatedly throwing two fair coins, with "success" when both coins come up "heads". What is the probability of having exactly 2 successes out of 8 trials?

Answer 1

Experiment : Throwing two fair coins.

Probability of both coins come up heads in a single throw = p = (1/2)*(1/2) =1/4 = 0.25

No of trials = n = 8

No of successes = x = 2

Probability of success = p = 0.25

The probability of having exactly 2 successes out of 8 trials is given by:

P(x=2) = 28*0.0625*0.1780

=0.3115

ANSWER: The probability of having exactly 2 successes out of 8 trials is 0.3115.