"Debra Dalgleish" wrote...
You can use an array formula to total the top scores. For example, with
scores in cells B2:B100 --

=SUM(LARGE(B2:B100,ROW(INDIRECT("1:3"))))

To array enter the formula, hold the Ctrl and Shift keys, then press Enter.
....

If the number of values to average is small (subjective, but 3 is definitely
a small number), and if you're hardcoding the 2nd arg to LARGE anyway
("1:3"), why not use

=SUM(LARGE(B2:B100,{1,2,3}))

which doesn't have to be entered as an array formula?