00:01
All right, we are told that in a certain community, 20 % of families own dogs.
00:12
And given that a family owns a dog, 20 % of dog owners also own cats.
00:27
We also know that 25 % of the total families own cats.
00:32
And so what i've done to the left is i've written these out in probability notation.
00:36
So the probability that a randomly selected family owns a dog is equal to 0 .2.
00:41
The probability that given a randomly selected family owns a dog that they own a cat is 0 .2, and the probability that a randomly selected family owns a cat is 0 .25.
00:51
And so the first question is just asking us, what is the probability that a randomly selected dog owns, or sorry, the probability that a randomly selected family owns a dog.
01:01
Well, that is just going to be equal to 0 .20 % which is given to us of the problem.
01:07
This is a percentage of families that own a dog...