Davinosky
Excel doesn't care about the value of your numbers, that is your role
You can use the Averageifs() function to get around this
eg: If your data is in A1:A8 the following will, help out
=AVERAGEIFS(A1:A8,A1:A8,"<50")
If you want to use a formula to derive a cut off point in B1
then use: =AVERAGEIFS(A1:A8,A1:A8,"<"&B1)
Averageifs is only available in excel 2007-2013
For Excel 97-2003 use:
=SUMIF(A1:A8,"<50")/COUNTIF(A1:A8,"<50")
or
=AVERAGE(IF(A1:A8<50,A1:A8,""))Ctrl+Shift+Enter