Answer: b) 18 inches per year
Explanation:
Each time x goes up by 1, y goes up by 18
slope = rise/run
slope = (change in y)/(change in x)
slope = 18/1
slope = 18
You can also use the slope formula to get the same answer. Let's say we picked the points (2,36) and (3,54). We then would get
m = (y2-y1)/(x2-x1)
m = (54-36)/(3-2)
m = 18/1
m = 18
We get the same result as before.
Since x represents the number of years and y is the number of inches, the slope of 18/1 indicates an increase of 18 inches per 1 year, or just 18 inches per year.
