Can someone help explain this to me? I have several questions similar to this and I'm lost as to how to solve them.

You are studying for your final exam of the semester. Up to this point, you received 3 exam scores of 100%, 60%, and 76%. To receive a grade of B in the class, you must have an average exam score between 80% and 89% for all 4 exams including the final. Find the widest range of scores that you can get on the final exam in order to receive a grade of B for the class. Use interval notation.
A) [77,100]
B) [84,100]
C) [81,82]

Question

Can someone help explain this to me? I have several questions similar to this and I'm lost as to how to solve them.

You are studying for your final exam of the semester. Up to this point, you received 3 exam scores of 100%, 60%, and 76%. To receive a grade of B in the class, you must have an average exam score between 80% and 89% for all 4 exams including the final. Find the widest range of scores that you can get on the final exam in order to receive a grade of B for the class. Use interval notation.
A) [77,100]
B) [84,100]
C) [81,82]

triciaal · Answer

one approach 
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