TRUE or FALSE: It is particularly important not to use input data in model formulas, but to reference the spreadsheet cells that contain the data. In this way, if the data changes or if you want to experiment with the model, you need not change any of the formulas, which can easily result in errors. True False In the Excel Solver add-in, binary decision variables are designated with the choice in the drop down menu of the Add Constraint dialog box. dif bin = = int