The average annual tuition and fees at all 4-year institutions in the US in 2002 was $12,200 and in 2010 was $ 23,800.Let y be the average tuition and fees in the year x, where x = 0 represents the year 2002.

a) Write linear equation, in slope-intercept form, that models the growth in average tuition and fees at all 4-year institutions in the US in terms of the year x.

b) Use this equation to predict the average tuition and fees at 4-year institutions in the US in the year 2020.

c) Explain what the slope of this line means in the context of the problem.