Averaging a specific range of values from a reference point

Hi, I know this is kind of a noob question but, how would one go about finding the average of a range of values in a column from the top and bottom of a reference point ?
Example: Say i wanted to find the average of the values from row 6 +- 3 rows (Therefore rows 3,4,5,6,7,8,9)?
Any help would be appreciated.

1 x.xx
2 x.xx
3 x.xx
4 x.xx
5 x.xx
6 x.xx <------(reference point)
7 x.xx
8 x.xx
9 x.xx
10 x.xx
11 x.xx
12 x.xx
13 x.xx

That was helpful, thanks