document.write( "Question 1202053: Charlie has scored 89, 78, and 63 on his previous three tests. What score does he need on his next test so that his average (mean) is 75? \n" ); document.write( "

Algebra.Com's Answer #836669 by ikleyn(52803) $\"\"$ $\"About$

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\n" ); document.write( "Charlie has scored 89, 78, and 63 on his previous three tests.
\n" ); document.write( "What score does he need on his next test so that his average (mean) is 75?
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document.write( "Let x be the unknown score on his fourth exam.\r\n" );
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document.write( "Charlie wants  \r\n" );
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document.write( "     = 75,\r\n" );
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document.write( "or\r\n" );
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document.write( "    89 + 78 + 63 + x = 4*75\r\n" );
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document.write( "    230 + x = 300\r\n" );
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document.write( "          x = 300 - 230\r\n" );
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document.write( "          x = 70.\r\n" );
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document.write( "ANSWER.  Charlie needs to get 70 on the 4th exam.\r\n" );
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\n" ); document.write( "\n" ); document.write( "It is a typical problem on average.\r
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\n" ); document.write( "\n" ); document.write( "To see many other similar (and different) solved problems, look into the lessons\r
\n" ); document.write( "\n" ); document.write( "    - Solved problems on average scores, weight, height and temperature\r
\n" ); document.write( "\n" ); document.write( "    - Solved problems on average scores\r
\n" ); document.write( "\n" ); document.write( "    - Solved problems on average age \r
\n" ); document.write( "\n" ); document.write( "    - Miscellaneous problems on average values \r
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\n" ); document.write( "\n" ); document.write( "Consider these lessons as your textbook, handbook, tutorials and (free of charge) home teacher.\r
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