Table 1. Obtained frequencies of leading digits in textbooks and testbank.

		Benford dist.	Knight 3rd ed. end-of-chapter answers	Young 10th ed. end-of-chapter answers	Skoog 7th ed. end-of-chapter answers	Knight testbank answers	Knight testbank distractors	combined data
# entries			1644	2155	294	1485	5671	11249
	1	0.3010	0.2889	0.2858	0.3129	0.2774	0.2906	0.2883
	2	0.1760	0.1673	0.1689	0.1667	0.1872	0.1816	0.1774
	3	0.1249	0.1247	0.1128	0.1224	0.1428	0.1259	0.1253
	4	0.0969	0.0991	0.1104	0.1122	0.0875	0.1010	0.1011
i	5	0.0791	0.0803	0.0891	0.0714	0.0714	0.0890	0.0850
	6	0.0669	0.0803	0.0733	0.0646	0.0835	0.0615	0.0695
	7	0.0579	0.0566	0.0617	0.0510	0.0606	0.0531	0.0562
	8	0.0511	0.0535	0.0599	0.0340	0.0505	0.0474	0.0508
	9	0.0457	0.0493	0.0381	0.0646	0.0391	0.0497	0.0464
MAD 1			0.0050	0.0094	0.010	0.011	0.0054	0.0033
			close conform	accept. conform	accept. conform	accept. conform	close conform	close conform
SSD 2			4	9	12	15	3	2
			accept. conform	accept. conform	accept. conform	accept. conform	accept. conform	perfect conform

¹ MAD = Mean Absolute Deviation (see text for definition)

² SSD = Sum of Square Differences (see text for definition)

Obtained distributions of leading digits and measures of conformation to Benford’s Law for three textbooks, a multiple-choice testbank, and aggregate data