0.131x The bar graph on the right shows the average cost of room and board at four-year public and private colleges for four selected years from 2011 through 2017. The data can be modeled by f(x)=945x+3143 and g(x) = 3851e in which f(x) and g(x) represent the average cost of room and board at public four-year colleges in the school year ending x years after 2010. Use these functions to complete parts (a) through (c) below. Average Cost ($) Average Cost of Room and Board at Four-Year Colleges 16000- 14000 Public Colleges 12000 Private Colleges 10.921 10,610 10000- 80004973 5317 60004609 4000- 2000- 1927 5866 7596 a. According to the linear model, what was the average cost of room and board at public four-year colleges for the school year ending in 2015? The average cost in 2015 was $ (Round to the nearest dollar as needed.). 0- 2011 2013 2015 2017 Ending Year in School Year