I suck at math.

There is a ranking system that stores a rating from 1 to 3 (1 being bad, 3 being best).

So there is a list of thousands of ratings all from 1 to 3.

To get an average...add up all the ratings and divide by how many there are (simple enough).

But to display that as a score of 1 to 10, (instead of 1 to 3) how would you do that?