(05) descriptive stats with ti calcs
22-Feb-11
Descriptive Statistics on the TI Calculators
I.Entering data: In order to analyze data with your calculator it must be entered into a list. Use the STAT key and on the EDIT menu choose 1:Edit. You should see the lists: L1, L2, L3 … L6. (If these lists are not all there because they have been accidentally deleted you can “reset” the calculator.) If the list(s) that you want to use are empty you can go ahead and start entering the data into one of the columns (e.g.L1). If the column for a list is not empty, highlight the list’s name (e.g.L1) press the CLEARkey (do not presstheDEL key – this will delete the list name) and move down into the list to enter the data.
II.Creating a histogram: Once the data has been entered into a list (let’s say L1) you are ready to create a histogram. Use STATPLOT (2nd Y=). Enter on 1:Plot1, if it is Off turn it On,for Type: choose the histogram icon (the third graph icon) and then enter for Xlist the name of the list you have created (e.g. L1) leave Freq:1. Press GRAPH. If the histogram doesn’t appear you may have to use ZOOM and choose 9:ZoomStat (hopefully that will get your histogram to appear). This is probably not the same histogram that we have previously created with cutpoints at 30, 40, …. In order to get this histogram press WINDOW and make Xmin = 30, Xmax = 100, Xscl = 10, Ymin = –1, Ymax = 8.2, Xscl = 1, Xres=1.
III.Getting descriptive statistics: Press the STAT key and choose the CALC menu, pick
1:1-Var Stats and press ENTER, now enter your list name (to get L1 press 2nd and the 1 key) and then press ENTER. Note that the arrow at the bottom of the output screen means that you have to scroll down to get more of the results.
Exercise:
1.Enter the “kitten” data: 63 52 57 37 84 60 65 72 40 49 63 44 51 69 91 76 41 52 58 57 45 56 54 38 77into a list on your calculator.
2.Create the histogram on your calculator. (Show it to me.)
3.Compute the descriptive statistics with the calculator and give:
a. the sample mean = ______
b. the sample standard deviations = ______
c. the five-number summary______, ______, ______, ______, ______