Question

Is there another way to think through conditional probabilities without using a tree diagram?

Answer 1

When you say "think through", do you mean working out a specific exercise or understanding what conditional probabilities generally mean?

Answer 2

(I think I can help you in both cases!)

Answer 3

yes working out a specific excercise !?

Answer 4

?? help

Answer 5

Okay there's a formula for the conditional probability, which is P(A|B) = P(A and B)/P(B)

Answer 6

Have you seen that before?

Answer 7

yes!

Answer 8

Okay, cool! Would you like me to take you through a specific example to see how it works, or does that sort out your problem?

Answer 9

no I was just wondering if there was another way besides using that formula ? But if you want to show me an example that would be great too :)

Answer 10

I can draw a picture, if it helps.

Answer 11

post the conditional probability problem you are working on and we can work through it.

Answer 12

P(A|B) means that you know for sure that B has happened, and you want to know the chance of A happening now.

Answer 13

If B has already happened, then you know that you're somewhere inside the circle on the right (in my drawing). To find the probability of A also happening, you need to see how big the area marked "A and B" is compared to the whole of the circle B.

Answer 14

That's why you get the formula P(A and B) / P(B).

Answer 15

Perfect! I think I understand it better haha. My professors sucks, but have a great day guys!

Answer 16

You too :)

Answer 17

Great job of explaining things @BasketWeave