So, in order to find the difference between the two ending balances, you have to subtract the smaller number from the larger one. The difference between $315,000 and $270,000 is $45,000. Now we have to find how much of a percentage $45,000 is. In order to do that, we split $315,000 into 100 peices, which would be $3150. That means that $3150 is 1% of $350,000. $45,000 is equal to 14.2857143% (simplified to %14.3) of $315,000. To check this, we multiply $3150 by 14.3, and we get the answer $45,000.
The net increase/decease from 2011-2012 would be 14.3%
I may have finished this question differently than others do, but you get the same answer! Hope this helped :)
