Question 537120
what is the probability of getting 6 tails in 10 trials of tossing a coin? need to solve using the approximation methoed and the binomial distribution
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Binomial: n = 10 ; p = 1/2
P(x = 6) = 10C6*(1/2)^6*(1/2)^4 = 210/2^10 = 0.2051
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Normal Approximation:
Find P(5.5 < x < 6.5)
mean = np = 10*0.5 = 5
std = sqrt(npq) = sqrt(5*1/2)) = 1.58
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z(5.5) = (5.5-5)/1.58 = 0.3165
z(6.5) = (6.5-5)/1.58 = 0.9494
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P(5.5<x<6.5) = (0.3165<z<0.9494) = 0.2046
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Cheers,
Stan H.
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