Data Analysis question, please HELP?

Question

What would be an appropriate bin size for a histogram with the following data:

75
53
78
76
72
48
67
78
76
81
63
55
63
77
90
74
64
64
87
71
66
79
77
73
70
71
75
69
82
75
70
85
76
78
59
63
72
72
75
54

Answer 1

You have about 28 data points from 48 to 90. I'd go with bins of 5 spaces. There may be a rule of thumb about this, but I don't recall it.