You have three identical, uniform, square pieces of wood, each with side length L. You stack the three pieces of wood at the edge of the horizontal top of a table. The first block extends a distance L/4 past the edge of the table. The next block extends a distance L/4 past the edge of the first block, so a distance L/2 past the edge of the table. The third block extends a distance L/4 past the edge of the block beneath it, so 3L/4 past the edge of the table. The stack is unstable if the center of mass of the stack extends beyond the edge of the table. Calculate the horizontal location of the center of mass of the three-block stack. Suppose that the origin of the horizontal x-axis is at the edge of the table, and the x-axis points toward the table's center.