Question

help.

Answer 1

what you needed to do is look at the hours that you have and arrang in to group i.e how many of the hour fall with in 0-9 hrs and so on

Answer 2

take for example how may form you group of 60,25,86,56,45,48,90,75,30,67,36,80,15,32,65,31 studied 0-9 hr or 10-19 hr and tally the number and then you will know the proper frequency table to select.