1. Auto sales ($ thousands), household income ($ thousands) and population (thousands) of 10 metropolitan areas were collected ("Auto sales data.xlsx"):
   1. Using household income and population, fit a multiple regression model to forecast auto sales. Provide the equation of the line fit and interpret the slope parameters
   2. Evaluate the model in part (a)
   3. Modify the model in part (a) to test whether population has a non-linear effect on auto sales (while still using household income as an independent variable). Provide the equation of the line fit. Does population have a non-linear effect? Explain
   4. Using multiple measures, compare the models in parts (a) and (c). Which model fits the data better? Explain

DATA:

Area	Auto_sales	Household_income	Population
1	185792	23409	133.17
2	85643	19215	110.86
3	97101	20374	68.04
4	100249	16107	99.59
5	527817	23423	289.52
6	403916	19426	339.98
7	78283	18742	89.53
8	188756	18553	155.78
9	329531	21953	248.95
10	91944	16358	102.13