Find the percent of the increase or decrease.

Original:4500
New:4005

the percent is lower which is 40%

Set it up in words:
4005 is what percent of 4500?
Now make the words into numbers:
4005=4500x
x=0.89
89% decrease.
If you don't get it please let me know. :)

If 4005 is 89% of 4500, then the percent decrease must have been 100 - 89 = 11%. Another way of doing the same thing is:

difference is decrease of 4500-4005 = 495.

[495/4500] x 100 = 11%

Oh right, sorry forgot the last step