Example: Suppose you have a company that sells t-shirts to retail stores, and the price you charge depends on how many shirts the store buys. If a store buys 20 shirts or less, you charge $8 per shirt. If a store buys more than 20 shirts, they pay $8 each for the first 20 shirts, and then $6 per shirt for anything above 20. (That means 20 shirts would cost $160 total, and 21 shirts would cost $166 total.) In this situation, the cost in dollars) of buying x t-shirts is the piecewise function 8x if 0 20. f(x) = You enter this function into Excel using an IF command as follows: = IF(value is in stated domain, apply this formula, otherwise apply this formula) For this example, let's suppose our input value is in Cell A2, then the IF command will look like this: = IF(A2 20. Enter this formula into Column C (rows 2-8) in the spreadsheet, while continuing to use Column A as your input variable column. Example to Use for Column D: This is the same situation and formula as Column C, but we want to do just a little bit more. If you think about it, you can' fx XXXX A B C D 1 Local Store Cost ($) 0 2 3 4 5 6 T-Shirts Ordered 0 5 10 15 20 25 30 40 80 120 Non-local Store Cost ($) XXXX XXXX XXXX XXXX XXXX XXXX XXXX 160 7 310 340 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 Sheet1