I have a feedback sheet that i need to calculate an average on the rating
given.

the feedback rating is 1-4 with 1 being bad, 4 being good.
It currently looks like this:
RATING 1 2 3 4
NUMBER 5 39 113 227

So 5 people have given a rating of 1, 39 people have given a rating of 2 etc
etc

How can i calculate the avereage rating....ie our average rating is 3.7 etc?

Thanks