Overdraft fees have become an important piece of a bank's total fee income. Suppose the following table gives the bank revenue from overdraft fees (in billions of dollars) from 2004 through 2009. Here, x = 4 corresponds to 2004.

Year, x 4 Revenue, y 24.5 29 33 34 35 36 (a) Find an equation of the least-squares line y for these data. (Round all numerical values to two decimal places.) (b) Use the result of part (a) to estimate the average rate of increase in overdraft fees over the period under consideration. (Round your answer to two decimal places.) the result of part (a) to est billion/yr (c) Assuming that the trend continued, what was the revenue from overdraft fees in 2014? (Round your answer to two decimal places.) billion