1 cm = 0.393701 inches.
Multiply total cm by conversion factor:
91 cm x 0.393701 = 35.8268 inches per day.
1 day = 24 hours
Divide total inches by number of hours:
35.8268 inches / 24 hours = 1.4928 inches per hour. ( Can round to 1.5 inches per hour if necessary)
