Solve the problem.
-Suppose that a family has 5 children and that the probability of having a girl is $\frac { 1 } { 2 }$. What is the probability of having at least four girls?
A) $0.3125$
B) $0.1563$
C) $0.1875$
D) $0.0313$

Question

Quizplus · Accepted Answer

The probability of having at least four girls is the sum of the probabilities of having exactly four girls and exactly five girls. Using the binomial probability formula, calculate these probabilities and add them: $P(X=4) = \binom{5}{4} \left(\frac{1}{2}\right)^4 \left(\frac{1}{2}\right)^1 = 5 \times \frac{1}{32} = 0.15625$ and $P(X=5) = \binom{5}{5} \left(\frac{1}{2}\right)^5 = 1 \times \frac{1}{32} = 0.03125$. Adding these gives $0.15625 + 0.03125 = 0.1875$.

Solve the Problem 12\frac { 1 } { 2 }21​ What Is the Probability of Having at Least Four

Solve the Problem $\frac { 1 } { 2 }$ What Is the Probability of Having at Least Four