Comparing Proportional Relationships
Student Summary
When two proportional relationships are represented in different ways, we can compare them by finding a common piece of information.
For example, Clare’s earnings are represented by the equation y=14.50x, where y is her earnings in dollars for working x hours.
The table shows some information about Jada’s earnings.
| time worked (hours) | earnings (dollars) |
|---|---|
| 7 | 92.75 |
| 4.5 | 59.63 |
| 37 | 490.25 |
If we want to know who makes more per hour, we can look at the rate of change for each situation.
In Clare’s equation, we see that the rate of change is 14.50. This tells us that she earns $14.50 per hour. For Jada, we can calculate the rate of change by dividing her earnings in one row by the hours worked in the same row. For example, using the last row, the rate of change is 13.25 since 490.25÷37=13.25. This tells us that Clare earns 1.25 more dollars per hour than Jada.
Visual / Anchor Chart
