The formula for conditional probability (Edexcel GCSE Statistics): Flashcards
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Practise the cards
10 cards from this deck
What is the formula for conditional probability?
What is the formula for conditional probability?
P(B|A) = P(A and B) / P(A)
How do you interpret P(B|A)?
How do you interpret P(B|A)?
Probability of B given that A has happened.
What indicates independence in events?
What indicates independence in events?
P(A|B) = P(A) and P(B|A) = P(B)
How to find P(B|A) using a Venn diagram?
How to find P(B|A) using a Venn diagram?
Number of outcomes in A and B / Number in A.
Why is it important to check if events are independent?
Why is it important to check if events are independent?
It simplifies calculations, P(B|A) = P(B).
What's a key point about P(B|A)?
What's a key point about P(B|A)?
It’s the probability of B assuming A has already happened.
How can you use the formula to find P(A and B)?
How can you use the formula to find P(A and B)?
Multiply P(B|A) by P(A).
Tiles: 7 white, 4 white X. Find P(X|white)
Tiles: 7 white, 4 white X. Find P(X|white)
4/7
P(B|A)=0.6 and P(A)=0.2. Find P(A and B)
P(B|A)=0.6 and P(A)=0.2. Find P(A and B)
0.12
If P(A)=3/10 and P(B|A)=1/2, find P(A and B)
If P(A)=3/10 and P(B|A)=1/2, find P(A and B)
P(A and B)=3/20