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# S1 probability help watch

1. Would some kind person take the time to help me with this question? I'm very stuck...

Isobel plays football for a local team. Sometimes her parents attend matches to watch her play.

A is the event that Isobel's parents watch a match

B is the event that Isobel scores in a match

You are given that P(B|A) = 3/7 and P(A) = 7/10

(i) Calculate P(AnB)

For this, I did: P(AnB)=7/10 x 3/7 =21/70

How do I work out B for this? I tried to rearrange it and got 2.3 or something but I know this is wrong...

I need to draw a venn diagram and I know the intersect is 0.3 but how do I work out the other two semi circles?...

I put that B= 0.2

It then asks me to say whether theyre independent and I've said that .7x.5 doesnt = .3 so theyre not independent..

The next part of the question says:

By comparing P(B|A) with P(B) explain why Isobel should ask her parents not to attend?? I have no idea..

2. anyoneeeeee
anyoneeeeee
You'll get a better response in the maths forum.

I've moved it for you.
4. have you tried to draw a Venn Diagram ?

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Updated: December 3, 2014
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