Find the probability. Round to the nearest ten-thousandth when necessary.
-A family has five children. The probability of having a girl is 1/2. What is the probability of having At least 4 girls?
A) 0.1563
B) 0.0313
C) 0.3125
D) 0.1875

Question

Quizplus · Accepted Answer

The probability of having at least 4 girls means having either 4 girls or 5 girls. Using the binomial probability formula, P(X=k) = C(n, k) * (p^k) * ((1-p)^(n-k)), where n=5, p=1/2, and k is the number of girls. Calculate for k=4 and k=5, then sum the probabilities: P(4 girls) = C(5, 4) * (1/2)^4 * (1/2)^1 = 5 * 1/32 = 5/32, P(5 girls) = C(5, 5) * (1/2)^5 = 1/32. Total probability = 5/32 + 1/32 = 6/32 = 0.1875.

Find the Probability