The question seems to be asking for the constant of proportionality from the given data, which represents the number of paper towel rolls per case. To find the constant of proportionality, you divide the number of paper towels by the number of cases for each pair of values to see if that ratio is the same across the board.
Let's calculate the ratio for each pair of numbers:
1. For 12 rolls per 1 case: 12 / 1 = 12
3. For 36 rolls per 3 cases: 36 / 3 = 12
5. For 60 rolls per 5 cases: 60 / 5 = 12
10. For 120 rolls per 10 cases: 120 / 10 = 12
It appears that, in each case, the number of paper towel rolls per case is 12, since dividing rolls by cases consistently gives the number 12.
Therefore, the constant of proportionality is 12 rolls per case. In the parentheses provided, you would write (12).
(12)