Please could someone help me with the following? I wish to compare two proportions and would normally use a pooled estimate theta = (n1p1+n2p2)/n1+n2 and the normal approximation z-test where p1-p2 / sqrt(theta(1-theta)(1/n1 + 1/n2)) is normal(0,1). However I have low sample sizes where n1<50 and n2<20. What test should I be using - I have unknown population size so am unsure as to whether I should use the hypergeometric or fishers exact?? Please respond to [log in to unmask] Thanks in advance ________________________________________________________________________________ This message has been checked for all known viruses by the Star Screening System http://www.star.net.uk/stats.asp