document.write( "Question 587371: Gina earns score of 65,78,85, and 82 on four tests. What grade must she earn on the next to have an average of 80?
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Algebra.Com's Answer #374086 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+x+\"$ = her grade on the next test
\n" ); document.write( "From the definition of an average:
\n" ); document.write( " $\"+%28+65+%2B+78+%2B+85+%2B+82+%2B+x+%29+%2F+5+=+80+\"$
\n" ); document.write( " $\"+%28+310+%2B+x+%29+%2F+5+=+80+\"$
\n" ); document.write( " $\"+310+%2B+x+=+400+\"$
\n" ); document.write( " $\"+x+=+90+\"$
\n" ); document.write( "She needs a 90 on the next test to average 80 \n" ); document.write( "

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