Question 259167
Use Chebyshev’s theorem to find what percent of the values will
fall between 10 and 26 for a data set with mean of 18 and standard
deviation of 2.
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10 is (10-18)/2 = -4 standard deviations to the left of the mean.
28 is (26-18)/2 = +4 standard deviations to the right of the mean.
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Chebyshev says "at least [1-(1/4)^2] = 15/16 of the data lies in
that interval. 
15/16 = 93.75%
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Use the Empirical Rule to find what two values 99.7% of the data
will fall between for a data set with mean 0 and standard deviation
of 12.
If 1-(1/k)^2 = 0.997, solve for "k".
(1/k)^2 = 0.003
1/k = 0.05477...
k = 18.257 (number of standard deviations to the right and to the left of zero)
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18.257*12 = 219.09
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99.7% of the data is between -219.09 and +219.09
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Cheers,
Stan H.