document.write( "Question 284162: After four geometry tests this nine weeks, Jessica's average score is 88%. What score does she need on her next test in order to raise her average to 90%? \n" ); document.write( "

Algebra.Com's Answer #206190 by oberobic(2304) $\"\"$ $\"About$

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An average of 88% means that the sum of the four tests divided by 4 = .88 = 88%.
\n" ); document.write( "S = sum of the 4 scores
\n" ); document.write( "S/4 = 88
\n" ); document.write( "S = 4*88
\n" ); document.write( "S = 352
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\n" ); document.write( "We need to find the value of the 'next' test that will bring the average to 90%.
\n" ); document.write( ".
\n" ); document.write( "(352+x)/5 = 90
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\n" ); document.write( "Multiply both sides by 5 to eliminate the denominator
\n" ); document.write( "352 + x = 450
\n" ); document.write( "x = 450 - 352 = 98
\n" ); document.write( ".
\n" ); document.write( "So, the student needs to score 98% on the fifth test to pull the average up to 90%.
\n" ); document.write( ".
\n" ); document.write( "Check by computing the average...
\n" ); document.write( "352 + 98 = 450
\n" ); document.write( "450 / 5 = 90
\n" ); document.write( ".
\n" ); document.write( "Answer: The student needs to score 98% on the fifth test to bring the average up to 90%.
\n" ); document.write( ".
\n" ); document.write( "Done. \n" ); document.write( "

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