so,

t = (Share_cell1 - Share_cell2)/sqrt (SE_cell1^squared + SE_cell2^squared)

Where SE = standard deviation of respondent level shares/sqrt(n)

I'm now weighting the respondent level shares by volume and reproportioning to yield an Expected Share of Volume.

I am uncertain of how to calculate SE for this problem. Would the 'n' I use be the effective base? (sum of volumes)^2 / (sum of squared volumes)?

confused.

Thanks.