Answer:
12.7% = X(11.4%) + Y(8.68%)
y = 1 - X
0.127 = 0.114X + 0.0868(1 - X)
0.127 = 0.114X + 0.0868 - 0.0868X
0.0402 = 0.0272X
X = 0.0402 / 0.0272 = 1.478
Y = 1 - 1.478 = -0.478
Y = -0.478 x $100,000 = -$47,800
Since value for Y is negative, it means that you must short sell the stock, i.e. borrow the stock, sell it, and then repurchase it later at a lower price.