document.write( "Question 1205948: To earn an A in a​ course, a boy must have a final average of at least 84​%. On the first four​ examinations, he has grades of 79​%, 85​%, 75​%, and 75​%. If the final examination counts as two ​grades, what must he get on the final to earn an A in the​ course?
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Algebra.Com's Answer #843064 by greenestamps(13200)\"\" \"About 
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\n" ); document.write( "The correction from the second tutor is not right. The grade on the final exam counts as much as two of the other grades, so in effect 6 grades are being averaged.

\n" ); document.write( "Here is an alternative method for solving a problem like this involving the average of numbers that are close together.

\n" ); document.write( "Consider how much each of the existing grades is above or below the desired average:

\n" ); document.write( "79: -5
\n" ); document.write( "85: +1
\n" ); document.write( "75: -9
\n" ); document.write( "75: -9

\n" ); document.write( "Together, the four grades are -22 compared to the desired average. To achieve the desired average, the final exam must be +22 compared to the desired average.

\n" ); document.write( "Since the final exam counts twice as much as each of the others, the grade on the final exam must be 22/2 = 11 over the desired average.

\n" ); document.write( "ANSWER: The minimum grade needed to achieve an average of at least 84% is 84+11 = 95%.

\n" ); document.write( "CHECK: 79+85+75+75+95+95 = 504; 504/6 = 84

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