To find the constant of proportionality from the data, we can calculate the ratio of pages read to time taken.
The constant of proportionality \( k \) can be calculated as:
\[ k = \frac{\text{Pages read}}{\text{Time (hours)}}. \]
Let's calculate \( k \) for each entry in the table:
-
For \( (12, 15) \): \[ k = \frac{15}{12} = 1.25. \]
-
For \( (1, 30) \): \[ k = \frac{30}{1} = 30. \]
-
For \( (112, 45) \): \[ k = \frac{45}{112} \approx 0.4018. \]
-
For \( (2, 60) \): \[ k = \frac{60}{2} = 30. \]
From this analysis, we can see that the consistent values of \( k \) are \( 30 \) for the entries \( (1, 30) \) and \( (2, 60) \).
Thus, the entry that shows a consistent ratio and thus represents the constant of proportionality is \( (1, 30) \).
So, the answer is:
(1, 30).