I have a spreadsheet where I record individual scores on a daily and weekly
basis. The spreadsheet consists of a column of names down the left side to
which I add new scores in the row next to each name every time someone
competes.

(example)
John 100 80 90 110
Amy 90 70 90 120 80
etc.....

I would like to create a formula which would search down to the end of the
populated row and take the average of ONLY the last 3 cells. Optimally, the
result would 'auto-update' every time I added scores to the end of the row.

Is this possible?