Frequency Table (Histogram)
Bins	Midpoint	Abs. Frequency	Rel. Frequency	Cumul. Rel. Freq.	Density
[40,60[	50	4	0.083333	0.083333	0.004167
[60,80[	70	3	0.0625	0.145833	0.003125
[80,100[	90	15	0.3125	0.458333	0.015625
[100,120[	110	8	0.166667	0.625	0.008333
[120,140[	130	13	0.270833	0.895833	0.013542
[140,160[	150	3	0.0625	0.958333	0.003125
[160,180]	170	2	0.041667	1	0.002083