Toxicology Example
Unit 2 Section 2					Wilcoxon Rank Sum Test
			Square Root Transformed	Square Root Transformed	Excel Rank	Excel Rank	Tied Rank	Tied Rank
	Control	Nitrofen	Control	Nitrofen	Control	Nitrofen	Control	Nitrofen
	27	29	5.20	5.39	4	6	4.5	7.5
	32	29	5.66	5.39	15	6	15.0	7.5
	34	23	5.83	4.80	18	1	18.5	1.0
	33	27	5.74	5.20	16	4	16.5	4.5
	36	30	6.00	5.48	20	10	20.0	11.0
	34	31	5.83	5.57	18	13	18.5	13.5
	33	30	5.74	5.48	16	10	16.5	11.0
	30	26	5.48	5.10	10	3	11.0	3.0
	24	29	4.90	5.39	2	6	2.0	7.5
	31	29	5.57	5.39	13	6	13.5	7.5
Sample Mean	31.400	28.300	5.595	5.315	132.0	65.0	136.0	74.0
Sample Variance	12.933	5.567	0.109	0.052			use this
Sample Std. Dev	3.596	2.359	0.330	0.228	T_U =		127
Sample Size	10.000	10.000	10.000	10.000			critical value
Separate Variance	1.850		0.016
c	0.699		0.678	95% UCL	Untransformed
df(separate)	15		15	Lower Bound	-0.29
t-statistic(separate)	2.279		2.202	Upper Bound	6.49
t-critical(separate)	2.131		2.131	Average Difference	3.10
p-value	0.019		0.022
Pooled Variance	9.250		0.080	95% UCL	Untransformed
df(pooled)	18		18	Lower Bound	-0.23
t-statistic(pooled)	2.279		2.202	Upper Bound	6.43
t-critical(pooled)	2.101		2.101	Average Difference	3.10
p-value	0.018		0.020
Sample Size Estimation
Pooled variance	9.250
Delta	1
P(Type I error)	0.05
Sample Size Needed	72