SOLUTION: I need some help with these questions that I do not understand. Please help! A) Find the binomial probability P(x=5), where (n=13) and p=0.70. B) Set up, without solving, the b

Algebra ->  Probability-and-statistics -> SOLUTION: I need some help with these questions that I do not understand. Please help! A) Find the binomial probability P(x=5), where (n=13) and p=0.70. B) Set up, without solving, the b      Log On


   



Question 525390: I need some help with these questions that I do not understand. Please help!
A) Find the binomial probability P(x=5), where (n=13) and p=0.70.
B) Set up, without solving, the binomial probability P(x is at most 5) using probability notation.
C) How would you find the normal approximation to the binomial probability P(x=5) in part A? Please show how you would caculate u ando in the formula for the normal approximation to the binomial, and show the final formula you would use without going through all the caculations.

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
I need some help with these questions that I do not understand. Please help!
A) Find the binomial probability P(x=5), where (n=13) and p=0.70.
P(x=5) = 13C5(0.7)^5*0.3^8 = 0.0142
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B) Set up, without solving, the binomial probability P(x is at most 5) using probability notation.
P(x >= 5) = 1 - P(0<= x <=4) = 1-0.0034 = 0.9966
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C) How would you find the normal approximation to the binomial probability
P(x=5) in part A? Please show how you would caculate u and o in the formula for the normal approximation to the binomial, and show the final formula you would use without going through all the caculations.
u = np = 13*0.7 = 9.1
sigma = sqrt(npq) = sqrt(9.1*0.3) = 1.6523
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Switching from Binomial to Normal:
P(x = 5) = P(4.5 <= x <= 5.5)
z(4.5) = (4.5-9.1)/1.6523 = -2.7840
z(5.5) = (5.5-9.1)/1.6523 = -2.1788
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P(4.5 <= x <= 5.5) = P(-2.7840<= z <= -2.1788) = 0.0120
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Cheers,
Stan H.
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