I think it is 432.sorry if it is wrong though. My bad calculation error.
We need to see the graph to be able to answer the question
For 5/8 it is .... 9/16
for 1/2 it is..... 2/3
Divide 1681 by 4 which is about 420.25 feet for length
Take the first point (2, 4) a scale factor of 3/2 will move the x coordinate 2 to 2*3/2 = 3 and the y coordinate 4 will be moved to 4*3/2 = 6.
So the image of ( 2, 4) will be ( 3, 6) TH other verices will move in the same fashion.