Question 5 [15 points] The question does not require the use of gretl. The graphs below depict the pth order polynomials for one independent variable. i. E( )) 11. E(y) ill. E(y) iv. E(y) a. [4 points] For each graph identify the order of the polynomial (e.g. first order, second order, third order, etc.) b. [8 points] Using the parameters 0, 1, 2, 3, etc., write an appropriate model form relating E(y) to x for each graph C. [3 points] The signs (+ or -) of many of the parameters in the models of part (b) can be determined by examining the graphs. For example, in graph (i), 1>0 Give the signs of those parameters for graphs ii, iii, and iv