I should be grateful if someone would tell me which equation to use for
calculating the sample size for the following situation:
I have looked at one particular biological property of 40 different
serotypes of a species of bacteria. Seven discreet forms have been
observed. There are 200 known serotypes in this species. Is 40 greater or
less than the minimum sample size assuming 95% confidence level? The
purpose of this experiment is to see if this species of bacteria can be
put into sub-groups according to this biological property.