Its true you could make the x-axis be type and compare the classes within or be classes and compare the type within.
Was that all the info given? Was there a first part to the question you have not shown?
Given the following data, if a comparative bar chart were to be made with percentages along the vertical axis, would row total or column total be used to calculate the percentages. The answer key says row total. How do you know that because the percentages could be of the class or domestic/international?
part a got me to state
part b says "If the vertical axis will show the Percentage of Passengers, would you use row, column or table totals to calculate the percentages?"
Apparently the answer is row because it is the independent variable. But is that a rule that the horizontal axis in a comparitive bar chart is the independent variable (and I guess the bars would be the dependent)?