Question $8$

The demand for good $x$ is estimated to be $Q_x^d=1700-2\mathrm{.}5P_x+3\mathrm{.}5P_Y+1\mathrm{.}5M+A_x,$ where $P_x$ is the price of $x,P_Y$ is the price of good $Y,M$ is income, and $A_x$ is the amount of advertisingon $x.$ Suppose the present price of good $x$ is $$50,P_Y=$$$100,M=$$$7,500,$ and $A_x=1,000$ units. Based on this information, what is the cross$-$price elasticity between goods $x$ and $Y?$ Give your answer with $4$ decimals.