Question

In five games you score 16,12,15,13 and 17 points.Write and solve an inequality to determine how many points must you score in the sixth game to have an average of at least 15 points.

Answer 1

First, review how you would go about finding an average.  If you look only at the 5 scores given, 16, 12, 15, 13 and 17, you'd add these up and divide the sum by the number of scores (5).

Now suppose there's a 6th game and your score is x.  

Add up the first 5 scores as before, and then add x to indicate the 6th score.  Divide this sum by 6 (because there are now 6 scores).  

Solve the resulting equation for x.  Show your work, please.