document.write( "Question 668684: Yasi is trying to get a B in her english class. To earn a B in the course, she must average a score of 80 on the 15 quizzes. She has taken 12 quizzes and averaged 78.25 points on them. How many points does Yasi need to average on the last 3 quizzess to earn a B in the course. \n" ); document.write( "

Algebra.Com's Answer #415779 by amazingrace333(11) $\"\"$ $\"About$

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To get a B or an average of 80 on 15 quizzes, the sum total of your scores must equal to 80 x 15 or 1200 points total.
\n" ); document.write( "If your average is 78.25 on 12 quizzes, you need to find out how many points out of the 1200 total that you still need. To do this, you multiply 78.25 x 12 to get the total points you have so far. 78.25 x 12 = 939
\n" ); document.write( "Now to find out how many points you need on the final 3 quizzes, subtract 939 from the original 1200 points needed. 1200-939 = 261
\n" ); document.write( "Since you are looking for the average grade you need on the final 3 quizzes, divide 261 by 3 to get the final average grade you need on the last 3 quizzes or 87.
\n" ); document.write( "1200/15 = 80
\n" ); document.write( "939+261 = 1200
\n" ); document.write( "939/12 = 78.25
\n" ); document.write( "261/3 = 87
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