Vlookup and mean formulas

Hello

I am hoping someone can help me with Vlook-up and calculating the mean


I have a single table where I want to search for a description called 'Field Blank', they I want to take the a specific value entered in a column and calculate the mean of the field blanks. Then I need to take the calculated mean value and input that into another column.

Currently my VLOOKUP formula is =VLOOKUP("Field Blank",$C$7:$I$23,7,FALSE).

I've attached the spreadsheet and highlighted the columns in question.

Struggles:
- retrieving a different value from the VLOOKUP formula when there is a different value the field blanks
- how to calculate the mean of the values from Vlookup.

Hopefully this makes sense. I know theres a way to do this.