To find the estimated number of patrons that borrow novels, you can set up a proportion based on the data from the survey.
From the survey:
- 3 out of 80 patrons borrow novels.
We can represent this as: \[ \frac{3}{80} \]
To find the estimated number of patrons who borrow novels in the entire library, which has 345 patrons, we set up the equation: \[ \frac{3}{80} = \frac{x}{345} \]
Where \( x \) is the estimated number of patrons borrowing novels. Cross-multiplying gives: \[ 3 \times 345 = 80 \times x \]
Calculating \( 3 \times 345 \): \[ 3 \times 345 = 1035 \]
Now, we have: \[ 1035 = 80x \]
To find \( x \), divide both sides by 80: \[ x = \frac{1035}{80} \]
Calculating \( \frac{1035}{80} \): \[ x = 12.9375 \]
Rounding to the nearest whole number: \[ x \approx 13 \]
Thus, the estimated number of patrons who borrow novels when they visit the library is: \[ \boxed{13} \]