The table lists the average annual costs (in dollars) of tuition and fees at public four-year colleges for selected years. Answer part (a) through (c). Year 1993 1995 1997 1999 2001 2003 2005 Tuition and Fees (in dollars) 2618 2870 3172 3320 3855 4634 5470 C (a) Use a calculator to find the least-squares regression line for these data, where x = 0 corresponds to 1993, x=2 corresponds to 1995, and so on. ya