Question 429569: Please assist me with my homework:
Suppose E and F are two INDEPENDENT events. Pr(E) = 0.8 and Pr(E∩F) = 0.2. Find Pr(E U F).
Let the sample space of an experiment be S = {a, b, c, d, e}. Suppose Pr({a, b, c}) = 0.45, Pr(c) = 0.1, and Pr({c, d)} = 0.35. Find Pr(e).
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Suppose E and F are two INDEPENDENT events. Pr(E) = 0.8 and Pr(E∩F) = 0.2. Find Pr(E U F).
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You need to know Pr(F)
Since the events are independent Pr(E and F) = P(E)*P(F)
0.2 = 0.8*P(F)
P(F) = 0.25
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P(E U F) = 0.8+0.25-0.2 = 0.75
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Let the sample space of an experiment be S = {a, b, c, d, e}. Suppose Pr({a, b, c}) = 0.45, Pr(c) = 0.1, and Pr({c, d)} = 0.35. Find Pr(e).
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P(a,b,c,d,e) = 1
P(e) = 1-P(a,b,c,d)
= P(a,b,c)+P(d)
= 0.45+P(d)
= 0.45+[P(c,d)-P(c)]
= 0.45+[0.35-0.10]
= 0.45+0.25
= 0.70
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Cheers,
Stan H.
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