The lifetimes (in hours) of 50 electric bulbs of the same make are recorded as follows:
910, 1025, 980, 1030, 950, 890, 1120, 1075, 995, 985,
1010, 1045, 935, 990, 960, 870, 1005, 1080, 1105, 1055,
925, 975, 945, 980, 1020, 995, 1015, 960, 990, 970,
985, 1000, 950, 940, 1090, 1060, 1035, 1010, 930, 920,
1150, 940, 955, 1085, 1000, 980, 995, 965, 960, 985.
Proceed as directed:
(a) Begin the first class at 850 hours and, with class width 200 hours, write down the five continuous class intervals that will cover all the observations.
(b) Prepare the grouped frequency distribution table for the data using the intervals chosen in part (a).
(c) State which class interval contains the maximum number of bulbs.