Macrophytes Were Sampled at Each of 3 Depths in a Particular

Short Answer

Macrophytes were sampled at each of 3 depths in a particular region of Lake Opinicon. The macrophages
obtained at each depth were classified as to their genus and their dry weights were also determined. One
question that was studied was whether or not macrophyte dry weight differs at different depths and if the
dry weight depended on the type of macrophage. The number of explanatory variables in this part of the
study is ___________.
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