2. Use the regression features of a graphing calculator to find a function that models the edge of the vase.

- These directions are for the TI-83. Other calculators may have slight differences.
- Type the data into the calculator's lists
- STAT>EDIT
- If the lists already have numbers, clear them by placing the cursor on the list name, L1, press CLEAR, then ENTER.
- Type all the x coordinates in L1
- Type all the y coordinates in L2

- Find the function that models the data
- STAT>CALC>QUARTREG (Do NOT press ENTER yet),
- Insert Y1 by VARS>YVARS>Function>Y1
- Your home screen should read QuartReg Y1, now press Enter.
- If you press Enter too early, clear the screen and try again.

- The screen displays the 4th degree polynomial that models the edge of the vase. This function is also pasted in Y1. You can graph it. Set your window values so Xmin = 0 and Xmax = 200 and select ZOOM>ZOOMFIT to see your model.

- Press [APPS]
- Choose
**1 FlashApps** - Choose
**Stat/List Editor** - If the lists already have numbers, clear them by placing the cursor on the list name, list1, press [CLEAR], then [ENTER].
- Type all the x coordinates in list1
- Type all the y coordinates in list2
- Press [F4 Calc] to begin doing the regression
- Choose
**3 Regression** - Choose
**6 QuartReg** - Enter
*list1*for the X List and*list2*for the Y List. For Store RegEqn to: choose*y1(x)* - This function is also pasted in Y1. You can graph it. Set your window values so Xmin = 0 and Xmax = 200 and select ZOOM>ZOOMFIT to see your model.