Question 930669
Note: z = 0 (x value: the mean) 50% of the area under the curve is to the left and 50%  to the right
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one  standard deviation from the mean accounts for about 68% of the set 
two standard deviations from the mean account for about 95%
and three standard deviations from the mean account for about 99.7%.
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mean =  412, with a standard deviation of 90.
P(412 < x < 592) = (.95/2)  = .475  0r 47.5%