3. In 1997 the average CO, emissions of new cars in the UK was 190g/km. In 2005 the average CO, emissions of new cars in the UK had fallen to 169 g/km. Given Ag/km is the average CO, emissions of new cars in the UK n years after 1997 and using a linear model, (a) form an equation linking A with n. In 2016 the average CO, emissions of new cars in the UK was 120 g/km. (b) Comment on the suitability of your model in light of this information