document.write( "Question 320975: The arithmetic mean and standard deviation of a certain normal distribution are 13.5 and 1.5 respectively. what value is exactly 2 standard deviations less than the mean?
\n" ); document.write( "a)10.5 b)11 c)11.5 d)12 e)12.5 \n" ); document.write( "
Algebra.Com's Answer #229868 by Edwin McCravy(20062)\"\" \"About 
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2 standard deviations less than the mean
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document.write( "So we start with the mean, which is given as 13.5. Write that down\r\n" );
document.write( "like this:\r\n" );
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document.write( "13.5\r\n" );
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document.write( "Now we take the standard deviation, which is given as 1.5, and\r\n" );
document.write( "multiply it by 2 (because it says \"2 standard deviations\") and we\r\n" );
document.write( "get 1.5 x 2 which equals 3, which we write as 3.0.\r\n" );
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document.write( "Now since we want to make the mean, which is 13.5, less by\r\n" );
document.write( "2 standard deviations, we know that to make something less,\r\n" );
document.write( "we must subtract from it.  So underneath the 13.5. we write 3.0.\r\n" );
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document.write( "13.5\r\n" );
document.write( " 3.0\r\n" );
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document.write( "Next we subtract:\r\n" );
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document.write( "13.5\r\n" );
document.write( "-3.0\r\n" );
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document.write( "10.5  \r\n" );
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document.write( "Now we notice that choice a) is 10.5, so that's the\r\n" );
document.write( "correct answer.  Didn't take a rocket scientist, did it?\r\n" );
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document.write( "Edwin
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