document.write( "Question 1208136: If a student scores 85,79,92, and 100 on her math quizzes then what was her average grade?
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Algebra.Com's Answer #846333 by greenestamps(13200) $\"\"$ $\"About$

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\n" ); document.write( "By the basic method, using the definition of average directly....

\n" ); document.write( " $\"%2885%2B79%2B92%2B100%29%2F4=356%2F4=89\"$

\n" ); document.write( "ANSWER: 89

\n" ); document.write( "Or by a method which is sometimes easier in cases where all the numbers are \"close together\"....

\n" ); document.write( "(1) Using a quick examination of the given numbers, make a guess for the average. In this example, 90 should be close.

\n" ); document.write( "(2) Determine, for each given number, the \"over\" or \"under\" compared to your guess for the average; then find the total over or under.
\n" ); document.write( "85: -5
\n" ); document.write( "79: -11
\n" ); document.write( "92: +2
\n" ); document.write( "100: +10
\n" ); document.write( "total: -16+12 = -4

\n" ); document.write( "(3) Divide the total over or under by the number of quiz scores to find the average over or under
\n" ); document.write( "-4/4 = -1

\n" ); document.write( "Adjust your guess by that average over or under to get the actual average
\n" ); document.write( "90+(-1) = 89

\n" ); document.write( "ANSWER (again, of course): 89

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