document.write( "Question 251150: Calculate the mean A and the median B of this set of fifteen automobile speeds collected by a police officer: 72; 80; 62; 71; 71; 64; 65; 73; 66; 78; 81; 66; 64; 77; 66 . \r
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\n" ); document.write( "\n" ); document.write( "A.-2.6 B.-0.6 C.-4.4 D.1.4 E.4.4\r
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Algebra.Com's Answer #182899 by Edwin McCravy(20064) $\"\"$ $\"About$

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Calculate the mean A and the median B of this set of fifteen automobile speeds collected by a police officer: 72; 80; 62; 71; 71; 64; 65; 73; 66; 78; 81; 66; 64; 77; 66 .
\n" ); document.write( "What does A – B equal?
\n" ); document.write( "A.-2.6 B.-0.6 C.-4.4 D.1.4 E.4.4 \r
\n" ); document.write( "\n" ); document.write( "72; 80; 62; 71; 71; 64; 65; 73; 66; 78; 81; 66; 64; 77; 66
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document.write( "To find the mean\r\n" );
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document.write( "1. Add them\r\n" );
document.write( "2. Divide by the number of numbers\r\n" );
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document.write( "1.  72+80+62+71+71+64+65+73+66+78+81+66+64+77+66 = 1056\r\n" );
document.write( "2.  1056÷15 = 70.4 \r\n" );
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document.write( "That's the mean, 70.4\r\n" );
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document.write( "To find the median of an odd number of numbers.\r\n" );
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document.write( "1.  Arrange them in order smallest to largest\r\n" );
document.write( "2.  Pick out the number that's right in the middle.\r\n" );
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document.write( "1.  62; 64; 64; 65; 66; 66; 66; 71; 71; 72; 73; 77; 78; 80; 81\r\n" );
document.write( "2.  The number that's right in the middle of the list is the\r\n" );
document.write( "    one I've colored red.  It's 71.\r\n" );
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document.write( "A - B = average - median = 70.4 - 71 = -0.6  which is choice B\r\n" );
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document.write( "-----------------------\r\n" );
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document.write( "Incidentally when there are an even number of numbers, to\r\n" );
document.write( "find the median, there is no one number right in the middle,\r\n" );
document.write( "as there was here.  Instead there are TWO numbers right in \r\n" );
document.write( "the middle, and you have to add them and divide by 2 in \r\n" );
document.write( "order to get the median.  So it's not quite as easy to find\r\n" );
document.write( "the median when there are an even number of numbers as it\r\n" );
document.write( "is when there are an odd number.\r\n" );
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document.write( "Edwin

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