Final answer:
The formula y=2.6x + 212.6 is used to predict the number of citizens with a driver's license in millions for a given year after 2013, by substituting 'x' with the number of years since 2013 and solving for 'y'.
Step-by-step explanation:
The equation you provided, y=2.6x + 212.6, projects the number of citizens carrying a driver's license in millions (y) for each year after 2013 (x). To predict the number of licensed drivers for a given year, you can substitute the number of years after 2013 into the equation for 'x' and solve for 'y'. For example, to find the number of citizens with a driver's license in 2015, you set x to 2 (since 2015 is 2 years after 2013) and solve the equation: y = 2.6(2) + 212.6 = 5.2 + 212.6 = 217.8 million.