The scale factor here is 2.5 from the first rectangle to the second rectangle.
The length of the rectangle went from 6.5 to 16.25. The scale factor is the number that you multiply the first shape by to get the second shape.
You can write and solve the following equation to find the scale factor.
6.5k = 16.25 Divide both sides by 6.5
k = 2.5
It will be the same factor with the other measurements of 4.5 and 11.25.