TI-84 Plus and TI-84 Plus Silver Edition Guidebook

Note:

You can enter expressions and variables for elements.

4.

Press

Í, }, or † to update the list. If you entered an expression, it is evaluated. If you entered only a variable, the stored value is displayed as a list element.

When you edit a list element in the stat list editor, the list is updated in memory immediately.

Attaching Formulas to List Names

Attaching a Formula to a List Name in Stat List Editor

You can attach a formula to a list name in the stat list editor, and then display and edit the calculated list elements. When executed, the attached formula must resolve to a list. Chapter 11 describes in detail the concept of attaching formulas to list names.

To attach a formula to a list name that is stored in the stat list editor, follow these steps.

1.

Press

… Í to display the stat list editor.

2.

Press

} to move the cursor to the top line.

3.

Press

| or ~, if necessary, to move the cursor onto the list name to which you want to attach the formula.

Note:

If a formula in quotation marks is displayed on the entry line, then a formula is already attached to the list name. To edit the formula, press

Í, and then edit the formula.

4.

Press

ƒ ããä, enter the formula, and press ƒ ããä.

Note:

If you do not use quotation marks, the TI-84 Plus calculates and displays the same initial list of answers, but does not attach the formula for future calculations.

Note:

Any user-created list name referenced in a formula must be preceded by an

Ù symbol

(Chapter 11).

Chapter 12: Statistics 187

5.

Press

Í. The TI-84 Plus calculates each list element and stores it to the list name to which the formula is attached. A lock symbol is displayed in the stat list editor, next to the list name to which the formula is attached.

lock symbol

Using the Stat List Editor When Formula-Generated Lists Are Displayed

When you edit an element of a list referenced in an attached formula, the TI-84 Plus updates the corresponding element in the list to which the formula is attached (Chapter 11).

When a list with a formula attached is displayed in the stat list editor and you edit or enter elements of another displayed list, then the TI-84 Plus takes slightly longer to accept each edit or entry than when no lists with formulas attached are in view.

Note:

To speed editing time, scroll horizontally until no lists with formulas are displayed, or rearrange the stat list editor so that no lists with formulas are displayed.

Handling Errors Resulting from Attached Formulas

On the home screen, you can attach to a list a formula that references another list with dimension

0 (Chapter 11). However, you cannot display the formula-generated list in the stat list editor or on the home screen until you enter at least one element to the list that the formula references.

All elements of a list referenced by an attached formula must be valid for the attached formula. For example, if

Real

number mode is set and the attached formula is

log(L1)

, then each element of

L1

must be greater than 0, since the logarithm of a negative number returns a complex result.

When you use the shortcut menus, all values must be valid for use in the templates. For example, if you use the

n/d

template, both the numerator and demoninator must be integers.

Notes:

• If an error menu is returned when you attempt to display a formula-generated list in the stat list editor, you can select

2:Goto

, write down the formula that is attached to the list, and then press

‘ Í to detach (clear) the formula. You then can use the stat list editor to find the

Chapter 12: Statistics 188