Referring to TABLE 1, what percentage of calls lasted 15 minutes or longer?

TAB LE 1 The following are the durationa in minutea of a sample of longdistance phone calls made within the continental United States reported by one longdistance carrier. '11} Relative [l but less than 5 3?% 5 but less than 15 22% 1B but less than 15 15% 15 but less than 2t} 15% 2B but less than 25 We 25 but leaa than 35 71% 30 or more 2%