Question 1200683
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A friend has a 85% average before the final exam for a course. That score includes everything 
but the final, which counts for 15% of the course grade.
(a) What is the best course grade your friend can earn?
%
(b) What is the minimum score would your friend would need on the final to earn a 75% for the course?
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            In this my post,  I will solve/answer part  (b),  ONLY.



<pre>
That 85% average, which he just have, go to the course grade (= contribute) with the weight of (1-0.15) = 0.85.


Those percents of the final that he will earn in the future, go to the course grade (= contribute) with the weight of 0.15.


So, for question (b), you should solve this inequality

    0.85*0.85 + 0.15x >= 0.75.


From this inequality, find x

    x >= {{{(0.75 - 0.85*0.85)/0.15}}} = 0.18333...    <U>ANSWER to question (b)</U>
</pre>

Solved.