Final answer:
The most logical choice, based on the information provided, is that approximately 50% of National Public Radio listeners do not donate money to their local station.
Step-by-step explanation:
The question asks about the percentage of people who regularly listen to National Public Radio (NPR) but do not donate money to their local station. While the provided information does not give a direct answer to this, it mentions that about half of public broadcasting stations' budgets come from viewers and listeners, implying that the rest of the listeners and viewers do not contribute financially. Considering the options provided (10%, 30%, 50%, 70%, and 90%), the most logical choice within the context of the question seems to be 50%, as it aligns with the information that half of the budget comes from donations, and thus the other half of the audience might not be contributing.