Remember that the slope of a line never changes, so you can choose whatever 2 points you want and you will always get the same slope. Calculate the rise and run (You can draw it on the graph if it helps). The slope is 2/4, which , of course, you can simplify to ½.
Answer:
20%
Step-by-step explanation:
So, I would set this up as a proportion-
72 x
90 100
Cross multiply-
100 x 72 = 7200
Divide-
7200/90 = 80
Subtract-
100 - 80 = 20
So, it is a 20% decrease