Question 721016
The probability that an appliance is in repair is 0.5. If an apartment complex has 100 such appliances, what is the probability that at least 60 will be in repair? Use the normal approximation to the binomial.
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mean = np = 100*0.5 = 50
std = sqrt(npq) = sqrt(50*0.5) = 5
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P(59.5<= x <= 100.5) = ?
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z(59.5) = (59.5-50)/5 = -0.1
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z(100.5) = (100.5-50)/5 = 50.5/5 = 10.1
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= P(-0.1<= z <=10.1) = 0.5398
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Cheers,
Stan H.
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