The convenience of shopping on the Web combined with high-speed broadband access services is spurring online spending. The projected online spending per buyer (in dollars) from 2002 (x = 0) through 2008 (x = 6) is given in the following table. Year, x 1 2 3 4 5 6 0 503 544 590 Spending, y 635 679 720 761 (a) Find an equation of the least-squares line for these data. (Round all coefficients to one decimal places.) y= 10 (b) Use the result of part (a) to estimate the rate of change of spending per buyer between 2002 and 2008. (Round your answer to one decimal place.) per buyer per year