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	5	6	7	8	9
Revenue, y	24.5	28	33	35	37	38

(a) Find an equation of the least-squares line y for these data. (Round all numerical values to two decimal places.)