The variable the school board is most interested in understanding/explaining is the change in schoolwide standardized test scores. You were also given variables that indicated the curriculum type and the income of the households of students from each school. If this were a real research project, what other data would you collect to use as control variables? Why? In other words, what other variables might you collect that you might plausibly expect to have an impact on the change in test scores aside from income and the curriculum type? Give at least 4 examples and in each case explain why you would include them.