trying to average a column of numbers but only the numbers which are memco
from column B and SMF from column C

I was told DAVERAGE is the way to go but I can't get the formula right

Production Calendar (sheet 1)

john doe Memco SMF $20
joe garcia AAS SMH $13
jessie nelson Memco SMF $10
david toms Memco SMM $ 9


Wage Summary (sheet 2)

average wage of a Memco, SMF employee = ____


The answer would be $15