I have the following chart that I am supposed to find the percent increase in one step, not using a two step method.

10.5
12.5
14.9
17.7
21.1
25.1

When I do this (and round) I get about 19% increase for each one. (we are supposed to round.

Then I have another chart that we are supposed to find the percent decrease also using the one step method.

80.2
71.4
63.5
56.5
50.3
44.8

If I use the same method I get about 12% decrease each time but the answer says 11% each time. If I do it the opposite way, for example, 71.4/80.2 and then subtract from 1.00 I would get more like 11%.

I'm just not really certain of the methodology to get the correct 11% answer.

Thank you.