To determine the constant of proportionality from the data provided, we need to understand the proportional relationship between the time (in hours) and the number of pages read.
The constant of proportionality \( k \) can be calculated as:
\[ k = \frac{\text{Pages read}}{\text{Time (hours)}} \]
Let's compute \( k \) using each entry in the table:
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For \( (12, 15) \): \[ k = \frac{15}{12} = 1.25 \]
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For \( (1, 30) \): \[ k = \frac{30}{1} = 30 \]
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For \( (112, 45) \): \[ k = \frac{45}{112} \approx 0.4 \]
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For \( (2, 60) \): \[ k = \frac{60}{2} = 30 \]
Now we look for the ratio that reflects the constant of proportionality, specifically those values which yield the same ratio between pages read and time.
From the options given:
- \( (1, 30) \) gives a proportionality constant of 30.
- \( (2, 60) \) also gives a constant of 30.
- \( (15, 12) \) does not reflect a consistent ratio since it doesn't directly relate to the entries provided in the context of the proportional relationships mentioned.
As \( 30 \) is the constant of proportionality for both \( (1, 30) \) and \( (2, 60) \), we can conclude that the answer with the constant of proportionality is from the response (1, 30).
So, the final answer is:
(1, 30)