Question 1048253: I'm a little confused on this. Any help would be appreciated, thank you!
Use the normal distribution to approximate the binomial distribution and find the probability of getting 15 to 18 heads out of 25 flips. Compare this to what you get when you calculate the probability using the binomial distribution.
Write your answers out to four decimal places.
Thank you!
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Use the normal distribution to approximate the binomial distribution and find the probability of getting 15 to 18 heads out of 25 flips.
mean = n*p = 25(1/2) = 12.5
std = sqrt(npq)= sqrt(12.5*(1/2)) = 2.5
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Using the normal approximation::
z(14.5) = (14.5-12.5)/2.5 = 0.8
z(18.5) = (18.5-12.5)/2.5 = 2.4
P(14.5< x >18.5) = P(0.8< z < 2.4)) = normalcdf(0.8,2.4) = 0.2037
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Compare this to what you get when you calculate the probability using the binomial distribution.
Using the binomial distribution, binomcdf(25,1/2,18) - binomcdf(25,1/2,14)
= 0.2049
Write your answers out to four decimal places.
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Cheers,
Stan H.
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