Asign placed at the top of a hill on route 684 north of white plains says “8% grade. trucks use lower gear.” what do you think that “8% grade” what does it mean?

Asunflower was 20 1/2 inches tall. over the next 6 months, it grew to a height of 37 inches tall. what was the average yearly growth rate of the height of the sunflower? ? plz write a proportion to solve i will give you 100 points