How do I create a rating system?

What I want to do is create a rating system that has a running average, that updates every time I put a new rating in a designated cell.

For example, cell A2 would be my average rating, and A1 would be the designated rating cell for new entries.

So that I could enter a new number into A1, press return, and then A2 would be updated with the new average rating.

The A1 cell would then clear ready for a new entry.


Is this possible, if so, could anyone help with the solution?

It would be greatly appreciated.


Thanks,

Jeky.