the old faithful in Yellowstone alternates periods of eruption, which typically last from 1.5 to 4 minutes with periods of dormancy, which are considerably longer. The following table presents durations , in of 30 dormancy periods that occurred during a recent year

89 92 66 90 65 88 97 61 83

91 86 82 90 71 89 99 90 116

97 90 88 92 82 71 66 91 61

95 93 93

Construct a frequency distribution using a class 5 and using 55, as the lower class limit for the first class.