SOLUTION: the average mark on a test for six students was calculated to be 84. one of the student's marks was accidentally counted as 86 rather than the correct mark mark of 68. Calculate th

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Question 295065: the average mark on a test for six students was calculated to be 84. one of the student's marks was accidentally counted as 86 rather than the correct mark mark of 68. Calculate the correct average mark for these six students.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
the average mark on a test for six students was calculated to be 84.
one of the student's marks was accidentally counted as 86 rather than the correct mark mark of 68.
Calculate the correct average mark for these six students.
:
Let v = the sum of the 5 correct grades
:
%28v+%2B+86%29%2F6 = 84
Multiply by 6
v + 86 = 6(84)
:
v + 86 = 504
:
v = 504 - 86
:
v = 418
:
Find the average (av) with the correct mark of 68
av = %28418%2B68%29%2F6
av = 486%2F6
av = 81 is the correct average