2.8. Show that 11- i=1 ny n i=1 b. Follow the same steps to show = (-)(x)= nx y. c. Show that (y)(x) b = (1 - 1)2 d. Establish the commonly used formula xy-nxy b = 17 - 12 2.9. Interpretation of Coefficients Associated with a Binary Explanatory Variable. Suppose that x; only takes on the values 0 and 1. Out of the n observations, n take on the value x 0. The n observations have an average y value of y. The remaining n-n observations have value x and an average y value of y2. Use Exercise 2.8 to show that b = Y2 - Y1- 1