Table of Contents
Directly Proportional
Directly proportional: when one amount increases, another amount increases at the same rate.
The symbol for “directly proportional” is ∝
Inversely Proportional
Inversely Proportional: when one value increases, at the same rate that the other decreases.
Examples
| Directly Proportional | Inversely Proportional | |
| Have more workers | You pay more | Work time is shorter |
How many spending ∝ workers
Constant of Proportionality
Constant of proportionality is the value that relates two amounts.
| can be written as | note | |
| spending = 10 x workers | y = kx | where k is Constant of Proportionality |
| Work time = 10 / workers | y = k/x | where k is Constant of Proportionality |