document.write( "Question 448468: Student test grades were normally distributed, and grades between 62 and 86 were within three standard deviations of the mean. Find the mean and the standard deviation of the set of grades. \n" ); document.write( "

Algebra.Com's Answer #308576 by ewatrrr(24785) $\"\"$ $\"About$

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document.write( "Hi,
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document.write( "Student test grades were normally distributed
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document.write( "grades between 62 and 86 were within three standard deviations of the mean
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document.write( "   86-62 = 24   24/2 = 12 
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document.write( "Mean: 74       |62+12   or 84-12
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document.write( "SD = 4         |74 - 3*4 = 62  and 74 + 3*4 = 86 \n" );
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