according to a survey by the administrative management society, one'half of US companies give employees 4 weeks of vacation after they have been with...

according to a survey by the administrative management society, one'half of US companies give employees 4 weeks of vacation after they have been with the company for 15 years. find the probability that among six companies surveyed at random, the number that give employees 4 weeks of vacation after 15 years of employment is anywhere from 2 to 5.