Remark
That's quite a jump isn't it? The easiest way to do this is to find the fractional increase and change that to a percent.
Solution
7.25 * x = 11.75 Divide by 7.25
x = 11.75 / 7.25
x = 1.621
But the question says what is the % increase. That means you have to multiply 7.25 by something to get what 11.25
In all, you have to subtract 1 which gives 0.621
So % increase is 0.621 * 100% = 62.1%
Comment
We have to try this out.
7.25 * 62.1/100 = 4.50
7.25 + 4.50 = 11.75 just as it should.