SOLUTION: I'm trying to figure out the following problem. Assume the variable x is normally distributed with mean u=90 and standard deviation o=4 Find the indicated probability: P(80 <

Algebra ->  Probability-and-statistics -> SOLUTION: I'm trying to figure out the following problem. Assume the variable x is normally distributed with mean u=90 and standard deviation o=4 Find the indicated probability: P(80 <      Log On


   



Question 384288: I'm trying to figure out the following problem.
Assume the variable x is normally distributed with mean u=90 and standard deviation o=4 Find the indicated probability:
P(80 < x < 87)
I'm using a TI-83 Calculator & have entered the following information.
invNorm(.80,90,4)= 93.3665
invNorm(.87,90,4)= 94.5056
I'm not sure I'm solving correctly as the second solution should be smaller than 87. Right?

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Assume the variable x is normally distributed with mean u=90 and standard deviation o=4 Find the indicated probability:
P(80 < x < 87)
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Comment: normalcdf is used to give you probabilities.
InvNorm is used to give you z-values.
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Your Problem:
P(80< x < 87) = normalcdf(80,87,90,4) = 0.2204
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Cheers,
Stan H.
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