Problem 8.12, page 160 from Zar (1999)
Output from SigmaStat

Mann-Whitney Rank Sum Test           Wednesday, September 27, 2000, 15:12:39

Data source: Data 1 in Notebook

Normality Test:	Passed	(P = 0.319)

Equal Variance Test:	Passed	(P = 0.384)

Group      N     Missing	
males      7        0	
females    6        0	

Group     Median      25%      75%	
males    224.100   220.575   228.225	
females  224.050   223.400   230.200	

T = 47.000  n(small)= 6  n(big)= 7  P(est.)= 0.520  P(exact)= 0.534

The differences in the median values among the two groups are not great enough to
exclude the possibility that the difference is due to random sampling variability;
there is not a statistically significant difference  (P = 0.534)





Problem 8.13, page 159 from Zar (1999)
Output from SigmaStat

Mann-Whitney Rank Sum Test                Wednesday, September 27, 2000, 15:15:41

Data source: Data 2 in Notebook

Normality Test:	Passed	(P = 0.826)

Equal Variance Test:	Passed	(P = 0.310)

Group       N     Missing	
northern    7        0	
southern    8        0	

Group      Median       25%      75%	
northern   118.000   114.500   119.750	
southern   117.500   116.000   120.500	

T = 53.500  n(small)= 7  n(big)= 8  P(est.)= 0.817  P(exact)= 0.779

The differences in the median values among the two groups are not great enough to
exclude the possibility that the difference is due to random sampling variability;
there is not a statistically significant difference  (P = 0.779)