"T. Valko" wrote...
By missing data points I assume you numbers to average.
....
=AVERAGE(IF(F52:F107=E5,IF(ISNUMBER(K52:K107),K52 :K107)))
....

Why the IF call? With the following data in A1:B8,

F 1
F <blank
M 3
M 4
F 5
F 6
F 7
M 8

and F in A10, the array formula

=AVERAGE(IF(A1:A8=A10,B1:B8))

returns 4.75 (as per specs) rather than 3.8. The AVERAGE function
ignores cells which don't contain numbers.