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Basic Statistics on a TI-83/84 Entering Data in Lists There are six lists available: L1 through L6. You can store data in a list in either of two ways. 1. From the home screen. Press [2nd] [( ] and then enter each data item, separating them by commas. When you are finished entering data, press [2nd ][ ) ]. Then press [sto<] [ L1 ], if L1 is the list you wish to store the data in, and press [enter]. 2. From the STAT Editor. Press [STAT] and choose option 1:Edit by pressing 1 or [enter]. Cursor over to the list you wish to enter data in and type in each data item, pressing [enter] or the down arrow key after each one. *If you wish to clear an item, highlight it and press [del]. If you wish to clear the whole list, highlight its name at the top and press [clear] NOT [DEL]! Graphing Data Press [2nd] [y=] to access the STATPLOT screen. Highlight the number of the plot you want to use and press [enter]. Highlight [ON] and press enter. Use the left-right cursors to highlight the type of graph you wish: Scatterplot, xyLine, Histogram, ModBoxPlot (marks outliers), Boxplot, and NormProbPlot and then press [enter]. You may be prompted for further information. When you are done, press [Zoom] and choose option 9. The graph will be drawn in a suitable window. If you wish to see what that is, press [Window]. The calculator will assume the explanatory variable is in L1 and the response variable in L2, but you can change these while in STATPLOT by typing in new lists for x or y. One Variable Descriptive Statistics Press [STAT], highlight [CALC], select option 1:1–Var Stats. and press [enter], which copies the title to the home screen. Press [2nd] [STAT] to access the [LIST] menu and press the number of the list containing the data you wish to analyze. *If you have a second list which gives the frequencies of each value in the first list, type a comma, then retrieve the name of the second list just like you did the original. The press [enter] to calculate the statistics. Note: The lists are also available as [2nd] functions of the number keys 1 through 6. Thus [2nd] [ 4] accesses L4. Correlation and Regression First press [2nd] [0] to access the CATALOG. Cursor down until DiagnosticOn is highlighted. Press [enter] to copy it to the home screen and then [enter] again. This makes sure the correlation coefficient is shown. Now press [STAT], highlight [CALC] and select option 8, either by number or by highlighting and pressing [enter]. This copies LinReg(a + bx) to the home screen. Now select the list containing the data for the explanatory variable, type a comma, then select the list for the response variable. Press [enter] and the information for the regression equation will be displayed along with the values of r2 and the correlation coefficient r. Graphing the Regression Line You can graph the regression line you just found on your scatterplot of the two variables you used. Press [y=] and choose a line. Then press [VARS], then option 5 for Statistics. Highlight EQ and select option 1:RegEQ. This will copy the regression to be graphed. Press [Zoom], and select option 9 to get a good viewing window. Generating Random Integers Press [MATH], highlight [PRB] and press 5:randInt(. On the home screen, you put in three numbers in the parentheses: first the lowest integer you want to generate, then the largest integer you want to generate, then the total number of integers you want. If you just want one at a time, you may simply close the parentheses after the second number. Example: randInt (2,20,5) generates 5 random integers between 2 and 20 inclusive. Generating a Normal probability plot Take the sample data and enter it into a list of your choice. Then go to STATPLOT and turn on a statplot of your choice. Under ‘Type’ select the sixth graph icon. For ‘Data List’ put your list, and for ‘Data Axis’ choose X. Then select [Zoom] and option 9 for a good graphical display. Finding Confidence Intervals for Proportions Press [STAT], highlight [TESTS], cursor down to A: 1--PropZInt and press enter. At x, enter the number of 'successes' observed and at n, enter the sample size. Specify a confidence level. Highlight [Calculate] and press enter to calculate the interval. Hypothesis Testing for Proprotions Press [STAT], highlight [TESTS] and press 5: 1--PropZTest. At po type the null hypothesis proportion. At x type the number of "successes" in the sample and for n put the sample size. Next choose the type of alternative hypothesis, and then highlight 'Calculate' and press [ENTER]. If you want to see the P-value area on a normal curve, highlight 'Draw' and press [ENTER]. Finding Confidence Intervals for Means Population standard deviation known: Press [STAT], highlight [TESTS], and press 7: ZInterval. You can either select Data, in which case you will need to put the sample data in a list, or Stats, in which case you can enter the sample mean and population standard deviation. At n, give the sample size and then specify the desired confidence level (as a decimal). Finally, highlight Calculate and press [ENTER]. Population standard deviation unknown: Press [STAT], highlight [TESTS], and press 8: TInterval. You can either select Data, in which case you will need to put the sample data in a list, or Stats, in which case you can enter the summary statistics ( mean and standard deviation) for the data. At n, give the sample size and then specify the desired confidence level (as a decimal). Finally, highlight Calculate and press [ENTER]. Hypothesis Testing for Means Population standard deviation known: Press [STAT], highlight [TESTS] and press 1: Z--Test. You can either select Data, in which case you will need to put the sample data in a list, or Stats, in which case you can enter the summary statistics (mean and standard deviation) for the data. At µ0 put the value for the null hypothesis and at n, put the sample size. In the next line you select the type of test (2-sided or 1-sided) and finally you choose whether to just have the calculations or to see the associated z-distribution graph along with the P-value and its associated z-score. Highlight your choice and press [ENTER]. Population standard deviation unknown: Press [STAT], highlight [TESTS] and press 2: T--Test. You can either select Data, in which case you will need to put the sample data in a list, or Stats, in which case you can enter the summary statistics (mean and standard deviation) for the data. At µ0 put the value for the null hypothesis and at n, put the sample size. In the next line you select the type of test (2-sided or 1-sided) and finally you choose whether to just have the calculations or to see the associated t-distribution graph along with the P-value and its associated t-score. Highlight your choice and press [ENTER]. Finding p-values from a P2 – distribution Access the Distribution menu by pressing [2nd] [VARS]. Highlight 7: P2 cdf and press [ENTER] (or simply press 7). In the parentheses, type your P2 test statistic, then a comma, then 100 followed by another comma, and finally the df (degrees of freedom) for your test. Close your parentheses and press [ENTER]. The value you get will be the probability of getting a P2 statistic greater than or equal to your test statistic for your chosen degrees of freedom (the p-value for your test statistic).