answer with explanation

Zillow.com contains several hundred postings for two-bedroom apartments in your city. A random sample of n = 16 postings from Zillow.com resulted in a standard deviation of $276. If a new study was being planned with s. = 280 and the desired 95% margin of error is $100, how many postings need to be sampled? Determine the minimum appropriate value. (Give your answer as a whole number.) number of postings