I have no clue if I am posting this in the right place, forgive me!

If I post an ad on craigslist for 24 hours in New York City and I get an average of one response per minute from that ad, and the population of the metro area of NYC is about 18 million, is there a way to extrapolate about what percent of the population is showing an interest in my ad?

TIA!

~Marcie