To find the constant of proportionality, we can divide the number of rolls of paper towels by the number of cases ordered.
Let's analyze the data provided in the table:
- For 1 case: 12 rolls of paper towels → Ratio = 12 / 1 = 12
- For 3 cases: 36 rolls of paper towels → Ratio = 36 / 3 = 12
- For 5 cases: 60 rolls of paper towels → Ratio = 60 / 5 = 12
- For 10 cases: 120 rolls of paper towels → Ratio = 120 / 10 = 12
In each case, the constant of proportionality is 12.
Thus, the ordered pair showing the constant of proportionality from the data table is (1, 12).