Question

A researcher found that 55% of families in the United States have one child under the age of 21, 22% have two children under the age of 21, 15% have three children under the age of 21, 5% have 4 children under the age of 21and 3% have 5 or more children under the age of 21. If a family is selected at random, what is the probability the family has 1 or 3 children under the age of 21?

Answer 1

67% or 0.67

Explanation:

Given that:

P(1 child under age 21) = 55%

P(2 children under age 21) = 22%

P(3 children under age 21) = 15%

P(4 children under age 21) = 5%

P(5 or more children under age 21) = 3%

If a family is selected at random, what is the probability the family has 1 or 3 children under the age of 21?

P(1 or 3 children under age 21):

Either the selected family has 1 child under 21 years of age OR the selected family has 3 children under 21 years of age ;

P(1 child under age 21) + P(3 children under age 21)

= 55% + 15%

= 67% = 0.67