Katy sold 373k last week. This week she's probably selling around 340k.
Miley has a 45% lead on her now. At worst, the overall lead will decrease till 40% (If Miley's lead decreases to 35% in those 2 days which I doubt is possible) after the weekend.
So, 340 + 0.4(340) = 476.
I think 600k is possible, but it would be safer to set our exceptions in the 500k range.
