Intel, a computer chip manufacturer, reported $\$ 1265$ million in total revenue in $1986 .$ In 2005 the total revenue was $\$ 38.8$ billion. (Source: U.S. Securities and Exchange Commission.) Assuming an exponential model, find the growth rate $k$, to four decimal places, and write the revenue function $R,$ with $R(t)$ in billions of dollars. Then predict the company's total revenue for 2012.