Use the special multiplication rule to find the indicated probability.
-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)0.3125
B)0.0313
C)0.1875
D)0.1563

Question

Use the special multiplication rule to find the indicated probability.
-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)0.3125
B)0.0313
C)0.1875
D)0.1563

Quizplus · Accepted Answer

The probability of having at least 4 girls out of 5 children can be calculated by considering the scenarios of having exactly 4 girls and exactly 5 girls. The probability of having 4 girls and 1 boy is (5C4)(1/2)^4(1/2)^1 = 5/32. The probability of having 5 girls is (1/2)^5 = 1/32. Adding these probabilities gives 5/32 + 1/32 = 6/32 = 0.1875.

Use the Special Multiplication Rule to Find the Indicated Probability