Hi The

I have a sheet of student marks which potentially run across 12 weeks.
Each students needs to make a mandatory 8 contributions. If the
student makes 8 contributions, then I simply average the marks to come
up with a grade. Some of the columns have blank weeks where the
student does not make a contribution. I've arranged the students
names
in columns and the marks are in rows.

If the student makes less than 8 contributions, than s/he will lose 10
marks from their average for every contribution s/he is below 8. For
example, if s/he makes 6 contributions and the 6 marks average 80%,
than s/he will only receive 60%.

If the student makes more than 8 contributions than I deduct the
lowest
marks. Therefore, if the student makes 12 contributions, than I
deduct
the 4 lowest marks before calculating the average. For example, if
the
student receives the following marks: 78, 56, 95, 100, 61, 84, 77,
73,
94, 82, 71, 88. Then I omit 56, 61, 71 & 73 before calculating the
average.

In Col. Y, I've calculated the number of contributions the students
has made.
In Col. Z, I've calculated the average for all the contributions the
student has
contributed.

Beside each number grade, I've put the letter grade in the next
column.
However, I'm getting an error message [#value!] with the forumula that
I'm using: =IF(Y19<8,Z19-(8-
Y19)*10,AVERAGE(IF(A19:X19=LARGE(A19:X19,8),A19:X 19)))

Help would be greatly appreciated.

Cheers
Rick