Question 813424
use the normal distribution to approximate the following binomial probability: find the probability of rolling 40 or more 6's when rolling a fair die 180 times.
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u = np = 180(1/6) = 30
s = sqrt(npq) = sqrt(30(5/6)) = sqrt(25) = 5
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Find P(39.5 < x < 180.5)
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z(39.5) = (39.5-30)/5 = 4.5/5 = 0.9
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z(180.5-30)/5 = 150.5/5 = 30.1
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P(40 <= x <= 80) = P (0.9<= z <= 30.1) = normalcdf(0.9,30.1) = 0.1841
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Cheers,
Stan H.