Frequency Table (Histogram)
Bins	Midpoint	Abs. Frequency	Rel. Frequency	Cumul. Rel. Freq.	Density
[460,480[	470	2	0.033333	0.033333	0.001667
[480,500[	490	3	0.05	0.083333	0.0025
[500,520[	510	9	0.15	0.233333	0.0075
[520,540[	530	12	0.2	0.433333	0.01
[540,560[	550	9	0.15	0.583333	0.0075
[560,580[	570	11	0.183333	0.766667	0.009167
[580,600[	590	9	0.15	0.916667	0.0075
[600,620[	610	2	0.033333	0.95	0.001667
[620,640]	630	3	0.05	1	0.0025