World coal production You can download here (in excel format) a table giving the yearly world production of coal (in thousands of short tons). Fit the data set provided using the model P = a, + ajT + a,T + a3T where P is the world production (in thousands of short tons) of coal and T are the number of years since 1980 (i.e. T = 0 for 1980) Use 16 digits in your calculations and give the answers with at least 2 digits after the comma a, = aj = a2 = az = The root means squared error (RMSE) of the fit is :