User manual TEXAS INSTRUMENTS TI84PLUS

[. . . ] TI-84 Plus and TI-84 Plus Silver Edition Guidebook Note: This guidebook for the TI-84 Plus or TI-84 Plus Silver Edition with operating system (OS) version 2. 55MP. If your calculator has a previous OS version, your screens may look different and some features may not be available. You can download the latest OS education. ti. com/guides. Important Information Texas Instruments makes no warranty, either express or implied, including but not limited to any implied warranties of merchantability and fitness for a particular purpose, regarding any programs or book materials and makes such materials available solely on an "as-is" basis. In no event shall Texas Instruments be liable to anyone for special, collateral, incidental, or consequential damages in connection with or arising out of the purchase or use of these materials, and the sole and exclusive liability of Texas Instruments, regardless of the form of action, shall not exceed the purchase price of this product. [. . . ] This is a scatter plot of the residuals. Chapter 12: Statistics 181 Notice the pattern of the residuals: a group of negative residuals, then a group of positive residuals, and then another group of negative residuals. The residual pattern indicates a curvature associated with this data set for which the linear model did not account. The residual plot emphasizes a downward curvature, so a model that curves down with the data would be more accurate. The window variables are adjusted automatically, and the original scatter plot of timeversus-length data (plot 1) is displayed. 25. to highlight Calculate. Note: You can also use the VARS Y-VARS FUNCTION menu, ?Residuals are calculated and stored automatically in the list name RESID. The regression line and the scatter plot are displayed. Chapter 12: Statistics 182 The new function y=. 192x. 522 appears to fit the data well. Press ~ to turn on plot 2. Note: Step 19 defined plot 2 to plot residuals (RESID) versus string length (L1). 29. The window variables are adjusted automatically, and plot 2 is displayed. This is a scatter plot of the residuals. The new residual plot shows that the residuals are random in sign, with the residuals increasing in magnitude as the string length increases. With this model, the largest positive residual is about 0. 041 and the smallest negative residual is about L0. 027. Now that you have a good model for the relationship between length and period, you can use the model to predict the period for a given string length. To predict the periods for a pendulum with string lengths of 20 cm and 50 cm, continue with these steps. ~ 1 to display the VARS Y-VARS FUNCTION secondary menu, and then press 1 to select 1:Y1. Y1 is pasted to the home screen. Note: You can also use the YVARS (t a) shortcut menu to select Y1. 32. Based on the residual analysis, we would expect the prediction of about 0. 92 seconds to be within about 0. 02 seconds of the actual value. Chapter 12: Statistics 183 33. Since a string length of 50 cm exceeds the lengths in the data set, and since residuals appear to be increasing as string length increases, we would expect more error with this estimate. Note: You also can make predictions using the table with the TABLE SETUP settings Indpnt:Ask and Depend:Auto (Chapter 7). Setting Up Statistical Analyses Using Lists to Store Data Data for statistical analyses is stored in lists, which you can create and edit using the stat list editor. The TI-84 Plus has six list variables in memory, L1 through L6, to which you can store data for statistical calculations. Setting Up a Statistical Analysis To set up a statistical analysis, follow these steps. Displaying the Stat List Editor The stat list editor is a table where you can store, edit, and view up to 20 lists that are in memory. To display the stat list editor, press ?, and then select 1:Edit from the STAT EDIT menu. Chapter 12: Statistics 184 The top line displays list names. The number of the current column is displayed in the top-right corner. [. . . ] Turn the graphing calculator on and adjust the display contrast, if necessary, by pressing y } or ?. In Case of Difficulty Handling a Difficulty To handle a difficulty, follow these steps. If you cannot see anything on the screen, you may need to adjust the graphing calculator contrast. To darken the screen, press and release y, and then press and hold } until the display is sufficiently dark. The previous screen is displayed with the cursor at or near the error location. [. . . ]