A regional planner is studying the demographics in a region of a particular state. data on nine counties: She has gathered the following County El Paso Meridian Martin Pulasky White Arenas Saline Dade Ocala Median Income 48,157 48,568 46,816 34,876 35,478 34,465 35,026 38,599 33,315 Median Age 57.7 60.7 47.9 38.4 42.8 35.4 39.5 65.6 27.0 Type of County Coastal Coastal Coastal Non-Coastal Non-Coastal Non-Coastal Non-Coastal Non-Coastal Non-Coastal a) What is the estimated regression equation? b) Test for the significance of the equation. What is your conclusion? c) Test for the significance of each slope. What are your conclusions?