The total revenue for a company (in billions of dollars) can be approximated by the function f(x) = 41.6 ex, where x = 7 corresponds to the year 2007. (a) What was the total revenue in 2016? (b) What was the first full year in which revenue exceeded $135 billion? (a) The total revenue in 2016 was approximately $ billion. (Type an integer or decimal rounded to the nearest hundredth as needed.) (b) The first full year in which revenue exceeded $135 billion was (Type a whole number.)