Answer:
Cheesy Burger should hire four workers
Step-by-step explanation:
Number of Total revenues Marginal Marginal cost
workers per hour revenue per worker
1 $30 $30 $9
2 $48 $18 $9
3 $62 $14 $9
4 $72 $10 $9
5 $80 $8 $9
6 $84 $4 $9
The marginal revenue generated by the fourth worker ≥ marginal cost per worker ($10 ≥ $9).
But the marginal revenue generated by the fifth worker < marginal cost ($8 < $9).