Percentage totals, a math and formula problem.

Hello,

I don't know a lot about Excel (and I've never been great at math, either) and I've been tasked with updating a spreadsheet to include the most recent months data and I need to figure out how someone calculated a total and whether or not they're wrong. Unfortunately they didn't leave their formulas in it or I could just fill them over.

In one column there are labels and in the next are some percentages and a total. This is what it looks like:

Campus 1	24.61%
Campus 2	17.12
Campus 3	0.00%
Total	23.51%

Any help would be greatly appreciated. How does one total percentages? This is just one example, there're others.