How high will US7 be with nine more floors?
Do your math and get an approximate height.
IF assuming the nine added floors are of equal height as the original floors and the top fins stay the same off the main roofline, then a cross multiplication and division will give you the answer.
With the above assumption holding true, (things at the top could be modified), the new height of US7 would be approximately 515.8m or 1691 ft.
Lotta fun, lotta fun.