The table shows how household spending changes with income.
| income ($ per month) | spending ($ per month) |
|---|---|
| 3000 | 3150 |
| 3300 | 3375 |
| 3600 | 3500 |
| 3900 | 3825 |
| 4200 | 4050 |
| 4500 | 4275 |
What is the lowest level of income at which savings are positive?
Choose your answer
$3000
$3600
$3900
$4200