I have 11 cells that are part of my question, A1, C1, C2, C3, C4, C5, E1, E2, E3, E4 and E5. A user will have an option to input an arbitrary value such as 200 or 400 into cells A1, C1, C2, C3, C4 and C5. The user must always enter a value into cell A1, however, each cell C1 through C5 will be...