Statistics with the TI-83 calculator

Transcription

1 Statistics with the TI-83 calculator 1. To enter a data list: Press: STAT EDIT Begin typing your numbers into any of the six lists. If a list has data in it that you want to clear out: Highlight the name of the list. Press: CLEAR ~, 2. To make a histogram of data in a list. I will use L1 as my example. Press: 2nd Y= (this gives you the stat plot key) Highlight: ON histogram type in: Xlist: L1 Freq: 1 Type in: Xmin= (type in the smallest lower class limit or cut point) Xmax= (type in the largest lower class limit or cut point; this number must be larger than any number in the data set) Xscl=(type in the desired class width) Ymin= type -5 Ymax= (type in a guess of the largest frequency for any.class) Note: ZOOM 9 will automatically set the window Press: Graph 3. To determine frequencies and lower class limits of a histogram once you have it graphed: Press: TRACE 4. To make a histogram of a frequency table. Type: the data list into L~ and the frequency list into Press: 2 nd Y= (this gives you the stat plot key) Highlight: ON histogram type in: Xlist: Freq: L 2 Follow the directions in # 2 for setting up the window and graphing. 5. To obtain the following descriptive statistics from your calculator: Mean: Y ; sum of the list: ~x; sum of the square of each number in the list: ~",x2 ; Sample standard deviation: Sx; population standard deviation: crx; number in the list: n, minimum number: minx; 25th percentile: Q~;median: Med; 75 th percentile: Q3 ; maximum number: maxx Press: STAT CALC 1 (1-Var Stats will appear on the screen; type in the name of the list where you have stored the data) Press: ENTER

2 6. To make a boxplot of data in a list. I will use L~ as my example. Note: Press: 2nd Y= (this gives you the stat plot key) Highlight: ON boxplot type in: Xlist: L1 Freq: Type in: Xmin= (type in the smallest number in the list) Xmax= (type in the largest number in the list) Xscl=l Ymin= type 0 Ymax= 10 ZOOM 9 will automatically set the window Press: Graph To get 5 number summary for a data set when the boxplot is graphed: Press: TRACE To get multiple boxplots: Turn on STATPLOTS 2 or 3 and set Xmin and Xmax in the WINDOW to the smallest and largest numbers in all lists. 8. To graph a scatter plot: To make a scatter plot of data in two lists. I will use L~ and L 2 as my example. Note: Press: 2nd Y= (this gives you the star plot key) Highlight: ON scatter plot type in: Xlist: L~ L2 type in the smallest number for X) Xmax= (type in the largest number for x) Xscl=(type how far tick marks are apart) Ymin= (type in smallest number for Y) Ymax= (type largest number for Y) Yscl=(type how far tick marks are apart) ZOOM 9 will automatically set the window Ylist: L_~ Press: Graph Press: TRACE (to get the coordinates of each plotted point)

3 Normal Distribution: Statistics with the TI-83 calculator To find the proportion of data or probability of X between a lower bound and an upper bound: 2nd--Distr--2: normalcdf (lower bound, upper bound, mean, standard deviation) To find the value ofx associated with having a given area to the left of x: 2nd--Distr--3: invnorm(area, mean, standard deviation) Binomial Distribution: To set ~ug a binomial table with the probabilities of each x from 0 to n: Y= 2n --Distr--0: binompdf(n,p) 2n~t window (tableset) tblstart=0 Atbl=l 2nd graph (table) To find the sum of the probabilities ofx from 0 to a specified value of x: 2" ~--Distr--A: binomcdf(n,p,x) t distribution To find the probabilities.of the t distribution from a lower bound to an upper bound With a specified number for the degrees of fteedom: 2n~---Distr--5: tcdf(lower bound, upper bound, dr)

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5 ~ Using the TI To enter a data list: Press: STAT, then for 1 :EDIT Begin typing your numbers into any of the six lists. o If a list has data in it that you want to clear out: ~ Highlight the name of the list. Press: CLEAR and then ENTER " 1, 2. To make a histogram of data in a list: This example will consider L 1 as the list of data. o Press: 2 nd, then Y = (see Figure 1) o for l Plotl o~ Highlight: ON, Histogram (see Figure 2) (If necessary, type in: Xlist: L~ and Freq: 1) o o Type in: o Xmin = (type in the smallest lower class limit or outpoint) o Xmax = (type in the largest lower class limit or outpoint; ~ this number must be larger than any number in the data set) o Xscl = (type in the desired class width) o Ymin = type 0 or-2 o Ymax = (type in a guess of the largest frequency for any class) Press: GRAPH. Figure! 3. To make a histogram of a frequency table: o Type the data list into L~ and the frequency listinto L_~ Press: 2 nd, then Y = (this gives you the "Stat Plot" key) ~ for 1: Plotl o Highlight: ON; HiStogram (If n egessary, :.type in: Xlist: L~ and..freq L 2 ) " % o Follow the directions in #2 for setting up the window and:,graphing. To make a scatter~plo{~of data in twolists: ~ Enter your data lists into L~.and Li~ ~ Press:._?n~., ~ then. Y=.,. (this ~,ges you the "Stat P10t" key) :~... o for 1 Plotl k : ~ ~,~ o Press: EN~ER ~.".: ~..o~~ Highlighf: ON, scalier plot (sec Figure 2 above) o lfcalculalor dd~ not already de~mlt to these values, t~e in: Xlist: L~ and Ylist: L~ * Press: ZOOM - " Press: 9 for 9: ZoomStat - This. will make your window dimensions default to the data in your list (see Figure 3)

6 5. To graph a scatter plot with specific window dimensions: Create a scatter plot as in #4 above Instead of hitting ZOOM 9, do the following: o Xmin = (type in the smallest number for X) o Xmax = (type in the largest number for X) o Xscl = (type how far tick marks are apm~) o Ymin = (type in smallest number for Y) o Ymax = (type largest number for Y) o Yscl = (type how far tick marks.are apart) Press: GRAPH Press: TRACE (to get the coordinates of each plotted point) WINOOW X~in=-5 X~ax=5 Xscl=l Y~in=-lO Y~ax=2000 Vsol=l Xres=l Figure 4 To determine a Linear Model: Enter the data into L~ and L 2 Graph a scatter plot using steps 4 or 5 Press: STAT o Press: -> to CALC - Press: 4 for 4: LinReg (ax + b) (see Figure 5) - Press: ENTER o Now your viewing window will show the values of "a" and "b" that can be used for your linear equation (see Figure 6) EOIT~ TESTS l-var3tats 2: 2-Vat Stats Med-Med LimReg(ax+b) eg Cub i oreg?~quartreg Figure 5 LinReg ~=ax+b a= b= rz= r=-, Figure 6 e To graph the Linear Model created in,,step #6: o Press: Y and now move tim cursor to the Yi that you want your equation to appear Press: VARS Press: 5 for 5: Statistics... Press: -) to EQ (see Figure 7) for 1: RegE.Q (this is for Regression Equation) (Now your equation should appear in the Y= wind~w) Press: GRAPH (You should now see a straight line going through your data points in the scatter plot!) Figure 7