The standard unweighted means analysis is often employed in balanced designs where data loss is unrelated to the levels of the independent variables. In a proportional unbalanced design, where unequal but proportional cell frequencies have been planned, the standard unweighted means analysis is not appropriate when a random loss of data has occurred. A weighted harmonic means analysis is presented that incorporates all of the available data, preserves the planned proportionality of the design, and avoids the problems associated with the replacement of missing data with sample estimates.
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