The scale factor is:
\( 6,75/4,5 = 9/6 = 1,5 \)
So you divide the corresponding lengths and the ratio you get is the scale factor.
you can see that each length in copy is 1,5 times longer than in original drawing
i did the problem differently. first i did 6.75/9 and i got 75 for my answer. then i did 4.6/6 and got 75 fir my answer. i added 75 + 75 and got 1.5 for my final answer
0.75 that you calculated was the inverse scale. It was the scale factor for original drawing vs copy.
What you found out was that the original is 0,75 times smaller than the copy. In other words copy is 1,5 times bigger than the original (it is the same fact from different point of views) :) However the scale factor is 1,5, because you compare copy to original (not the opposite way around).