Let be the number of units (in thousands) that a company produces
and let be the profit (in tens of thousands of dollars). The
following table gives the profit for different levels of production.
| 2 | 4 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 |
| -1.5 | -4.1 | -6.6 | -7.4 | -8 | -7.4 | -6.6 | -4.5 | -1.5 | 1.9 |
Use the quadratic regression program to find a mathematical model for
.