Question

# The data are given in the two-way table. Which variable should be used as the explanatory variable? Explain.

Study design

A survey was designed to study how business operations vary according to their size. Companies were classified as small, medium, or large. Questionnaires were sent to 200 randomly selected businesses of each size. Because not all questionnaires were returned, researchers decided to investigate the relationship between the response rate and the size of the business. The data are given in the two-way table.
$$\text{Business size} \\ \begin{array}{l|r|r|r|r} && \text { Small } & \text { Medium } & \text { Large } & \text { Total } \\ \hline \text{Response?} & \text { Yes } & 125 & 81 & 40 & 246 \\ \hline &\text { No } & 75 & 119 & 160 & 354 \\ \hline &\text { Total } & 200 & 200 & 200 & 600 \end{array}$$
Which variable should be used as the explanatory variable? Explain.