1. The builtin data frame stackloss contains 21 data observations on four variables taken at a factor},r where ammonia is converted into nitric acid. The rst threee variables are AirJ-"low, UaterIemp, and Acidonc. The fourth variable is stack. loss. which measures the amount of ammonia which escapes before being absorbed. You can check the help le for the dataset by typing ?stackj low for more information about this data frame. (a) Make three scatterplots relating acid concentration and ammonia, water temperature and ammo nia. and air ow and ammonia. Label all the axes appropriately. Do these relationships appear to be Linear or nonlinear? (b) Use the function pairs() to obtain all pairwise scatterplots between the four variables. Identify pairs of variables where there might by linear or non linear relationships