=+journeys than scheduled are not desirable. For a service between Istanbul and Bursa in the Sea of Marmara, the ferries’ travel times are monitored for 15 days, four sample journeys each day. The results are shown in the table below:

MEAN (MINUTES)

(n 5 4) MINIMUM MAXIMUM 121 117 125 123 119 126 124 119 125 115 113 117 114 111 118 126 118 130 130 122 133 122 119 125 123 118 124 119 117 125 128 118 133 124 120 127 116 112 120 120 117 124 121 118 126