In Janie's homeroom, 45% of the students' families own a dog and 23% own a dog and a cat. What is the probability that a student's family owns a cat if the family owns a dog?

51,111%

Step-by-step explanation:

We know that 45% have a dog but no cat. While 23% have both a dog and a cat.

Then Pr (X has cat|X has dog) = Pr (X has dog and cat) / Pr (X has dog)

= Pr (X has dog and cat) / Pr (X has dog) = 0.23/0.45 = 0.51 ≈ 51,111%

The probability that a student's family owns a cat if the family owns a dog is 51,111%

51.1% is the correct answer.