Question 822243: A switch fails 5% of the time. A random sample of 15 switches has been pulled. What is the probability that:
a. Exactly 4 switches will fail?
b. Less than 3 switches will fail?
c. At least 4 switches will fail?
d. More than 2 switches will fail?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A switch fails 5% of the time. A random sample of 15 switches has been pulled. What is the probability that:
a. Exactly 4 switches will fail?
Ans: P(x = 4) = binompdf(15,0.05,4) = 0.0049
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b. Less than 3 switches will fail?
Ans: P(0<= x <=2) = binomcdf(15,0.05,2) = 0.9638
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c. At least 4 switches will fail?
P(4<= x <=15) = 1 - P(0<= x <=3) = 1 - binomcdf(15,0.05,3) = 0.0055
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d. More than 2 switches will fail?
P(3 <= x <= 15) = 1 - P(15,0.05,2) = 1-binomcdf(15,0.05,2) = 0.0362
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Cheers,
Stan H.
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