document.write( "Question 852547: in a certain distribution of numbers, the mean is 80 and the standard deviation is 8. At least what fraction of the numbers are between the following pairs of numbers. Give answers as common fractions reduced to lowest terms.\r
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Algebra.Com's Answer #513467 by ewatrrr(24785)\"\" \"About 
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document.write( "Hi,
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document.write( "P mean is 80 and the standard deviation is 8.
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document.write( " z = (96-80)/8 = 2  0r (64-80)/8 = -2
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document.write( "(64 < x < 96) = P( -2 < z < 2) = .955  0r 955/1000 = 191/500
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document.write( "Below:  z = 0, z = ± 1, z= ±2 , z= ±3 are plotted.  
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document.write( "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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