How do I add percentage uncertainty when calculating an average?

[ultimatebusta]

Homework Statement

I currently want to add 2 percent each with a relative uncertainty together:
$$\frac{53.3\% +/- 1\% + 65.8\% +/- 1\%}{2}$$

I'm not sure how I can add the percentage uncertainty.

Homework Equations

The Attempt at a Solution

I've concluded that the average is 59.55%, however I'm unsure about how to handling adding the percentage uncertainty.

 

[chemisttree]

When you are adding and subtracting, you add the uncertainties together. In this case you get +/- 2%. Don't forget to divide this by 2 as well.