A researcher uses ratio estimation Y^R=yˉxˉX\hat{Y}_R = \frac{\bar{y}}{\bar{x}} XY^R=xˉyˉX. Given yˉ=20,xˉ=10\bar{y}=20, \bar{x}=10yˉ=20,xˉ=10 and X=500X=500X=500, what is Y^R\hat{Y}_RY^R?
200200200
500500500
100010001000
400400400