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TI-84 Plus GRAPHING CALCULATOR MANUALJames A. Condor Manatee Community College Deanna L. Voehl Indian River State College

to accompany

Statistics: Principles and MethodsSixth Edition by

?? Johnson?? State University

JOHN WILEY & SONS, INC.

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ContentsPreface 1 2 3 4 5 6 7 8 9 Introduction Organization and Description of Data Descriptive Study of Bivariate Data Probability Probability Distributions The Normal Distribution Variation in Repeated Samples - Sampling Distributions Drawing Inferences from Large Samples Small Sample Inferences for Normal Populations

10 Comparing Two Treatments 11 Regression Analysis I; Simple Linear Regression 12 Regression Analysis II; Multiple Linear Regression and Other Topics

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PrefaceStatistics is an important field of study, now more so than ever. We are surrounded by statistical information in work and in our everyday lives. Many of us work in professions that require us to understand statistical summaries, and some of us work in areas that require us to produce statistical information. The art of teaching statistics has changed dramatically in recent years, with computational software eliminating the need for many of the previously taught techniques. The answers to many of the complex computations come easier and faster to students with todays calculators performing most of the work in elementary statistical analysis. The challenge to the instructor is to get the student to acquire a greater understanding of what (s)he is doing, with the calculator tending to the details of the computations. The TI-84 Plus calculator, by Texas Instruments, is a leading example of the progress in statistical technology. Texas Instruments has provided us with an advanced device at an affordable price that is capable of powerful statistical work and yet is still easy to use. This text will run through the statistical capabilities of the TI-84 Plus calculator. This text will follow the order of topics presented in Johnsons Statistics, sixth edition, published by John Wiley & Sons, Inc., but should also prove useful with other texts. It will not explain the underlying statistics but instead focus on how best to use the TI-84 Plus calculator in computing them.

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Chapter

1IntroductionUse of TechnologyStatistics is a field that deals with sets of data. After the data is collected, it needs to be organized and interpreted. There is a limit to how much of the work can be done effectively without the help of some type of technology. The use of technology, such as a calculator with enhanced statistical functions, can take care of most of the details of our work so that we can spend more time focusing on what we are doing and how to interpret the results. Technology can help us not only to store and manipulate data, but also to visualize what the data is trying to tell us. As we work with a calculator, we will be able to: Enter, revise, and store data. Perform statistical computations on stored data or entered statistics. Draw pictures, based on the data, to help us to understand what useful information can be inferred from that data. Advantages of Using a Calculator There are many good statistical software packages available, such as MINITAB, SAS, and SPSS. Excel also contains many statistical built-in functions, as well as supporting plug-ins for statistical work. Still, for the student starting to learn statistics, its hard to beat the advantages of using a powerful hand-held calculator. It is portable and easy to use in many different work environments. It has battery power that lasts far longer than that of a laptop computer. It is less expensive than a computer. It is less expensive than a statistical software package.

Advantages to Using the TI-84 Plus This calculator manual will focus on how to get the most out of using the TI-84 Plus calculator by Texas Instruments. The TI-83 was first released in 1996, improving upon its predecessors (the TI-81 and TI-82) with the addition of many advanced statistical and financial functions. The TI83 Plus and the TI-84 Plus have essentially the same features as the TI-83, but with increased memory capacity and a few extra statistical features. They are powerful calculators with advanced functions, but at the same time easy to use. Most complicated statistical computations are handled through menus which prompt you for the necessary input. Data entry and revision is handled through a Statistical List Editor that is similar to a spreadsheet in how it is used. Statistical graphs are handled through menus and important parts of the graph can be read by tracing along with the arrow keys. The calculators are built sturdily, and can withstand many falls off of student desks.

Entering and Revising DataThis chapter focuses on getting numbers into your calculator and storing them for the organization, interpretation, and analysis part of statistics. When you are not given the necessary statistics to perform calculations, you will need to enter data into the calculator to generate the statistics. We will learn how to do statistical calculations with the calculator in future chapters. Using the Statistical List Editor The Statistical List Editor in the TI-84 Plus calculator provides a convenient way to enter numbers and review them. Numbers from a data set can be stored in a list in the calculator so that we can keep numbers that are related to each other together. Example: Calories Consumed An individual is modifying eating habits and has kept track of calories consumed for the last 10 days, as follows:

1474, 1633, 1686, 1748, 1326, 1112, 1245, 1539, 1220, 1561

If we want to do any sort of analysis on these numbers, we will need to get them into the calculator and keep them together as a group.

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Accessing the Statistical List Editor Press the STAT key.

To input data or to make changes to an existing set of data values use the Edit function. (number one under the EDIT list). Press the number 1 key or press the ENTER key if 1: is highlighted.

Resetting the Statistical List Editor If the Statistical List Editor does not show the columns labeled as L1, L2, and L3, you can reset the Editor to its default settings by selecting SetUpEditor as follows: Press the STAT key. Press the 5 key. Press the ENTER key.

Once the Editor is set up, return to the Edit function. Entering Data in the Statistical List Editor

Type in the ten calorie counts under the column labeled L1. Press the ENTER key when you are done with one number and ready to move on to the next number.

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Type in 1474 and press the ENTER key. Type in 1633 and press the ENTER key. Type in 1686 and press the ENTER key. continue until all the data values have been entered.

Use the up and down arrow keys to go back and forth between the numbers. Try changing the value of one of the entries by typing in a new calorie count. Clearing a List of Data Values After a list of data values is no longer needed, you can delete the values by using one of the following methods: You can highlight each data value and use the DEL key. This method is slow and clears the list one data value at a time. You can highlight the list name, for example L1 at the top of the column, and press the CLEAR key and then press the ENTER key. You can go to the EDIT menu and press the number 4 key to clear list. Press the STAT key. Press the number 4 key. Press the 2nd key and then press the 1 key to get L1.

Press the ENTER key.

Entering Lists Directly to the Statistical Editor List The home screen is where you do most of your calculator work that doesnt involve menus. Wherever you are on your calculator, you can always get back to the home screen by pressing the 2nd key and then the MODE key to access the QUIT function. From the home screen, you can enter data into a list by typing it between a set of braces { and }, and separating the numbers by commas: {1474, 1633, 1686, 1748, 1326, 1112, 1245, 1539, 1220, 1561}

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Once youve typed the numbers in, you will want to save them. Use the store button STO followed by L1, L2 or any other list. ( L1 L6 are above the 16 keys, using the 2nd key.) When you press the STO key, the screen will display an arrow going to the right. Once youve entered a list from the Statistical List Editor, you can see the list by typing its name. For example, if you stored the calories in L1, typing L1 (2nd key then 1 key) on the home screen will display the lists contents. (You will need to use the left and right arrow keys to see all of the lists contents.) Entering Lists Directly to a Name You can also store data to a name that you create. From the home screen, you can save a list to a name by using the STO key. Moving the Named List to the Statistical List Editor The data is stored in the name CAL, but it is not stored as a list. In order to access CAL from the home screen, a list must be created as follows: Press the STAT key. Press the number 1 key. Press the key to highlight the name at the top of one of the columns. Press the 2nd key and then the DEL key to get to the INS (insert) function. Type in the name of your new list - CAL (note that the A-LOCK is turned on so you do not need to press the ALPHA key before each letter), Press the ENTER key. The numbers that you stored in CAL should now appear in the list. Create a Named List Within the Statistical List Editor The lists L1 through L6 are good places to work with data if you do not need to save the data. If you may need the data later and do not want to accidentally over-write it, you can give the data a name. A list can be named with 15 characters. The first character must be a letter A - Z or the angle symbol theta. The other characters can be a letter, a , or a number 0 - 9. To get letters from the keyboard, press the ALPHA