The gross domestic product (GDP) of the United States! in trillions of dollars, from 2011 through 2015 is approximately qr} = 0.06412 + o.473r+ 15's (0 s f g 7) where t is measured in years, with t = 0 corresponding to 2011.'t [n constructing this model, the government used actual GDP figures from 2011 and 2012 and estimates for the years 2013 through 2018. [a] What was the US. GDP in 2011? (b) What is the predicted U.S. GDP for 2018