The arithmetic mean of six grades is 87. If the lowest grade is dropped, the mean is 89. What is the lowest grade?
If the mean is 87, that means the sum of the grades is 6*87= 522. If the lowest grade is dropped that leaves 5 grades with an averagve of 89. SO the sum of those 5 is 5*89= 445. To find the grade subtracted, you find the difference of theses sums which is 522-445= 77 which is your answer.
Hope it helps!
Btw how many questions will you be asking?
No I didn't mean that, I just noticed a bunch of questions from the same user that's all.