The population of a town is recorded every year for 5? years with Year 0? being the town's population at the beginning of the record-keeping. The results are recorded in the table below.
| Year | Population |
|---|---|
| 0 | 19,266 |
| 1 | 18,158 |
| 2 | 17,045 |
| 3 | 16,323 |
| 4 | 15,599 |
| 5 | 14,790 |
a) Determine an exponential regression of the form y=ab^x using the least-squares method to fit this data, where y? is the town's population x? years after record-keeping began. Round each value to four decimal places.
b) Using the regression from a), what will the population of the town be at Year ?9??? Round to the nearest whole number.