SOLUTION: If a fair coin is tossed 200 times what is the probability that you will see between 80 and 120 heads? If the Normal approximation to the Binomial distribution applies, use it. If

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Question 440007: If a fair coin is tossed 200 times what is the probability that you will see between 80 and 120 heads? If the Normal approximation to the Binomial distribution applies, use it. If not use the Binomial distribution methods.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
If a fair coin is tossed 200 times what is the probability that you will see between 80 and 120 heads? If the Normal approximation to the Binomial distribution applies, use it. If not use the Binomial distribution methods.
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Use approx because np and nq are both greater than 10.
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Find P(79.5 <= x <= 120.5)
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mean = np = 200(1/2) = 100
std = sqrt(npq) = sqrt(100(1/2)) = 5sqrt(2)
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z(79.5) = (79.5-100)/5sqrt(2) = -5.798
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z(120.5) = (120.5-100)/5sqrt(2) = 5.798
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P(80 < x < 120) = P(-5.798 < z < 5.798) is approximately 1.0000
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Using the binomial dist I get P(80< x <12) = 0.9964
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Cheers,
Stan H.