SOLUTION: Confused...Please Help! The probability that a student has a Visa card (event V) is .70. The probability that a student has a MasterCard (event M) is .60. The probability that

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Question 137291: Confused...Please Help!
The probability that a student has a Visa card (event V) is .70. The probability that a student has a
MasterCard (event M) is .60. The probability that a student has both cards is .50. (a) Find the probability
that a student has either a Visa card or a MasterCard. (b) In this problem, are V and M independent?
Explain.
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
The probability that a student has a Visa card (event V) is .70. The probability that a student has a MasterCard (event M) is .60.
The probability that a student has both cards is .50.
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(a) Find the probability that a student has either a Visa card or a MasterCard.
The key word here is OR.
P(V or M) = P(V)+P(M)-P(V and M)
P(M or M) = 0.60 + 0.7 - 0.5 = 0.8
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(b) In this problem, are V and M independent? Explain.
We don't know if they are independent.
To check that you would have to compare P(V)*P(M) and P(V)*P(M|V)
But we don't know P(M|V) so we cannot judge on independence.
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Cheers,
Stan H.