An engineer was assigned the task of calculating the average time spent by vehicles waiting at trafficsignals. The signal timing (in seconds) would then be modified to reduce the pressure of traffic. The observations of average waiting time during the month of January are:

58	63	58	12	24	47
46	29	42	68	33
43	37	39	52	35
44	35	49	36	64
53	28	55	27	53
55	64	37	31	61

(a) Obtain the quartiles.

(b) Obtain the 80th percentile.

(c) Construct a histogram.