<PRE><B>Question 1205948</B>
&lt;br&gt;
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.&lt;br&gt;
Here is an alternative method for solving a problem like this involving the average of numbers that are close together.&lt;br&gt;
Consider how much each of the existing grades is above or below the desired average:&lt;br&gt;
79: -5
85: +1
75: -9
75: -9&lt;br&gt;
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.&lt;br&gt;
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.&lt;br&gt;
ANSWER: The minimum grade needed to achieve an average of at least 84% is 84+11 = 95%.&lt;br&gt;
CHECK: 79+85+75+75+95+95 = 504; 504/6 = 84&lt;br&gt;
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