document.write( "Question 1205574: Hi
\n" ); document.write( "In a math class 40% are girls. The average score for the girls was 82.3% while the average score for the boys was 72.5%. What was the average score of all the students.
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Algebra.Com's Answer #842470 by ikleyn(52788) $\"\"$ $\"About$

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\n" ); document.write( "In a math class 40% are girls. The average score for the girls was 82.3%
\n" ); document.write( "while the average score for the boys was 72.5%.
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document.write( "We may think that the class is 25 students, in all,\r\n" );
document.write( "of which 40%, or 10 students, are girls and the rest, 25-10 = 15 students, are boys.\r\n" );
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document.write( "Then the total score of girls is 10*82.3, while the total score of boys is 15*72.5.\r\n" );
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document.write( "Then the total score of the class is  10*82.3 + 15*72.5 = 1910.5.\r\n" );
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document.write( "Hence, the average score of the class is   = 76.42.\r\n" );
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document.write( "    Notice that this number 76.42 is the same as  0.4*82.3 + 0.6*72.5 = 76.42.\r\n" );
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document.write( "    So, we could get the answer using this simple formula (!)\r\n" );
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document.write( "ANSWER.  The average score of all the students in the class is 76.42.\r\n" );
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