SOLUTION: please help me solve this problem. thank in advance! A normally distribited population with 200 elements has a mean of 60 and a standard deviation of 10. the probability that the

Algebra ->  Probability-and-statistics -> SOLUTION: please help me solve this problem. thank in advance! A normally distribited population with 200 elements has a mean of 60 and a standard deviation of 10. the probability that the       Log On


   



Question 616224: please help me solve this problem. thank in advance!
A normally distribited population with 200 elements has a mean of 60 and a standard deviation of 10. the probability that the mean of a sample of 25 elements taken from this population will be smaller than 65 is:
A. 0.0166
B. 0.0228
C. 0.3708
D. 0.0394

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A normally distribited population with 200 elements has a mean of 60 and a standard deviation of 10. the probability that the mean of a sample of 25 elements taken from this population will be smaller than 65 is:
mean of the sample means: 60
std of the sample means: 10/sqrt(25) = 2
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z(65) = (65-60)/2 = 5/2
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P(x-bar < 65) = P(z < 5/2) = normalcdf(-100,5/2) = 0.9938
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Your posted answer options are not the answer to your
posted problem.
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Cheers,
Stan H.
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A. 0.0166
B. 0.0228
C. 0.3708
D. 0.0394