Yes.
If for example, the original value was 200 and it was reduce by 30, so that the value became 200- 30= 170, the "percentage reduction" is [tex]\frac{30}{200}= .15 or 15%. Notice that the percentage is base on the original amount, 200, not the new amount, 170. We are saying that the reduction is 60% of the original amount.
(Because both reductions and increases are computed as based on the base amount, which can vary if your doing a succession of percentages, if the amount were now to increase by the same percentage, 15%, since this is a new calculation, the "base" is now the new amount 170 so the increase amout would be .15(170)= 25.5 and now the new amount would be 170+ 25.5= 195.5, NOT the orignal 200.)
attraction signs
You must try this linkwww.netcomuk.co.uk/~jenolive/percent.html