When Will PS4 Double Xbox One?

[trixiemafia86]

Check this out.
For PS4 to double X1 by the End of December 2014 for instance,
if we count from June:
PS4 will have to sell 550,000 or more each month and X1 would have to sell 200,000 or less each month from June to December.
This is just an example. But you guys get the point.