document.write( "Question 200311: A student has earned scores of 87, 81, and 88 on the first 3 of 4 tests. If the student wants an average (arithmetic mean) of exactly 87, what score must she earn on the fourth test? \n" ); document.write( "
Algebra.Com's Answer #150584 by nerdybill(7384)\"\" \"About 
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A student has earned scores of 87, 81, and 88 on the first 3 of 4 tests. If the student wants an average (arithmetic mean) of exactly 87, what score must she earn on the fourth test?
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\n" ); document.write( "Let x = score on fourth test
\n" ); document.write( "then
\n" ); document.write( "(x+87+81+88)/4 = 87
\n" ); document.write( "(x+256)/4 = 87
\n" ); document.write( "Multiplying both sides by 4:
\n" ); document.write( "(x+256) = 87*4
\n" ); document.write( "(x+256) = 348
\n" ); document.write( "x = 348-256
\n" ); document.write( "x = 92 (score for fourth test)\r
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