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Calculating conditional probability

G
The usher at a wedding asked each of the 80 guests whether they were a friend of the bride or of the groom.
Here are the results:
Bride
Groom
29
30
20
1
Given that a randomly selected guest is a friend of the groom, find the probability they are a friend of the bride.
P (bride groom)​

User Gsiener
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2 Answers

0 votes

Answer:

the answer is 3/5

Explanation:

on Khan

User Fmark
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4 votes

Complete Question

Calculating conditional probability

The usher at a wedding asked each of the 80 guests whether they were a friend of the bride or of the groom.

Here are the results:

Bride :29

Groom :30

BOTH : 20

Given that a randomly selected guest is a friend of the groom, find the probability they are a friend of the bride.

P (bride | groom)​

Answer:

The probability is
P(B|G) = (2)/(3)

Explanation:

The sample size is
n = 80

The friend of the groom are
G = 30

The friend of the groom are
B = 29

The friend of both bride and groom are
Z = 20

The probability that a guest is a friend of the bride is mathematically represented as


P(B) = (29)/(80)

The probability that a guest is a friend of the groom is mathematically represented as


P(G) = (30)/(80)

The probability that a guest is both a friend of the bride and a friend of the groom is mathematically represented as


P(B \ n \ G) = (20)/(80)

Now


P(B|G) is mathematically represented as


P(B|G) = (P(B \ n \ G))/(P(G))

Substituting values


P(B|G) = ((20)/(80) )/((30)/(80) )


P(B|G) = (2)/(3)

User Jeremy Seekamp
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