Rajib is at a conference in Boston presenting his work that studies how a variable x relates to another variable y. As usual, he regresses y on x, and is going to discuss the slope coefficient during his talk. He runs the following model: yi = 0 1xi i However, he spills coffee on his laptop and his OLS estimates are gone. He calls Doruk to ask for the number. Doruk sends Rajib the slope coefficient from the following regression: xi = 0 1yi ui Rajib questions Doruk, but Doruk argues that "the model is linear anyway, just invert 1." That is, xi =0 1yi ui = yi =0 xi ui 1 1 and thus Doruk is arguing: 1 = 1 . 1 (a) Show that Doruk is just being stupid. (b) Overhearing the conversation, Yashaswini asks: "What if Corr(x, y) = 1