Question

A plant grows at a constant rate. Daniel records the height of the plant eachweek. The unit rate is measured in inches per week. What is the constant ofproportionality?18 inches15 inches12 inchesWeek 4Week 5Week 6

Answer 1

In order to determine the constant of proportionality, use the following formula:

m = (y2 - y1)/(x2 - x1)

where x1 and y1 are the height of the plant at week x1, and x2 and y2 are the height of the plant at the week x2.

Use, for example:

x1 = 5 (week 5)

x2 = 6 (week 6)

y1 = 15 inches

y2 = 18 inches

replace the previous values into the formula for m:

m = (18 - 15)/(5 - 6)

m = 3/1

m = 3

Hence, the unit rate is 3