Let the weight be "W" and the cost be "C".
We can check if they are proportional to each other by finding the constant.
W = kC
3 = k × 53.97
3 ÷ 53.97 = k
k = 0.056
Now we repeat it with the second one
W = kC
10 = k × 179.90
10 ÷ 179.90 = k
k = 0.056
The constant is the same, so yes, they are proportional.
