The true proportion, which is the population proportion of adults who pay for subscriptions they do not use, is represented by the value in the middle of the 95% confidence interval. The confidence interval you've provided is from 0.352 to 0.548.

To find the true proportion, we calculate the midpoint (or average) of the interval:

$\text{True proportion} = \frac{0.352 + 0.548}{2} = \frac{0.900}{2} = 0.45$

Thus, the estimated true proportion of adults who pay for subscriptions they do not use is 0.45 or 45%.

Let me know if you'd like any further clarification or if you have more questions!

Related questions:

1. How can you interpret a confidence interval in terms of sample data?
2. What is the formula for calculating the confidence interval for a population proportion?
3. How does the sample size affect the width of the confidence interval?
4. What is the difference between a point estimate and a confidence interval?
5. How would you interpret a confidence interval if the true proportion was outside the range?

Tip: The width of a confidence interval indicates the precision of your estimate; a narrower interval means higher precision, and a wider one means more uncertainty.