School officials are concerned about dropping scores across the district in 5th grade mathematics standardized tests. Specifically, students are struggling with addition and subtraction of fractions. The district mathematics curriculum coordinator has identified three new programs for revamping how 5th graders are taught these skills. The curriculum director has been instructed to set up a research study to be conducted over the first three months of the next school year to decide which program, if any, should be adopted. How would you set up the required research study? Be sure to include in your discussion the following the number of groups you would need, how many students in each group, the selection teachers to participate, how you would collect and analyze the data. and identify potential covariates/confounding variables that you would need to control.