SOLUTION: Suppose you have a normal distribution of test scores with a mean of 50 and a standard deviation of 5. What percentage falls between 40 and 60?

Question 896238: Suppose you have a normal distribution of test scores with a mean of 50 and a standard deviation of 5. What percentage falls between 40 and 60?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Suppose you have a normal distribution of test scores with a mean of 50 and a standard deviation of 5. What percentage falls between 40 and 60?
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40 is 2 standard deviations below the mean.
60 is 2 standard deviations above the mean.
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Chebyshev says the answer is "at least 1 - (1/2)^2 = 75%
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The standard normal distribution says
P(-2 < z <= 2) = normalcdf(-2,2) = 0.9545 = 95.45%
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Cheers,
Stan H.
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