Question

What is the probability of flipping a coin seven times and getting heads four times? A. 16.4 b.27.3 c. 5.5 d.0.8

Answer 1

0.2734

Explanation:

Using the binomial probability relation :

P of success, p = 1/2 ; q = 1 - p = 0.5

Number of trials, n = 7

Number of successful outcomes = 4

Recall:

P(x = x) = nCx * p^x * q^(n-x)

P(x = 4) = 7C4 * 0.5^4 * 0.5^3

P(x = 4) = 35 * 0.5^4 * 0.5^3

P(x = 4) = 0.2734

Probability of obtaining 4 heads = 0.2734