MathBits.com Table of Contents Statistics
Histograms

Given the data set
 {13, 3, 10, 9, 7, 10, 12, 8, 6, 3, 9, 6, 11, 5, 9, 10 13, 8, 7, 7},
create a histogram representing this data.

1.  CLEAR out the graphs under y = (or turn them off).

2.  Enter the data into the calculator lists. Choose STAT,  #1 EDIT
     and type in entries.  (See Basic Commands for entering data.)

pic1


3.  To plot a histogram:
    
Press 2nd STATPLOT and choose #1 PLOT 1.  You should
        see the screen at the right.  Be sure the plot is ON, the
        histogram icon is highlighted, and that the list you will be using
        is indicated next to List.   Freq: 1 means that each piece of
       data will be counted one time.


pic2


4.  Controlling the graphical display of a histogram:
      To see the histogram, press ZOOM and #9 ZoomStat.
       (ZoomStat automatically sets the window to an appropriate size
       to view all of the data.)  Press the TRACE key to see on-screen
       data about the histogram.  The spider will jump from bar to bar
       showing the range of values contained within each bar and the
       number of entries from the list (n) that fall within that range.

pic4


•  Under your WINDOW button, the Xscl value controls the width of each bar beginning with
   
Xmin. Choosing ZoomStat will automatically adjust Xmin, Xmax, Ymin, Ymax, and Xscl. 
    (If you wish to see EACH piece of data as a separate interval, set the Xscl to 1.)
•  
Integer values for Xscl will be the easiest to read.
•   If you wish to adjust your own viewing window, remember that (
Xmax-Xmin)/Xscl  must be less than
    or equal to 47 for the histogram to be seen in the viewing window. 
•  A value that occurs on the edge of a bar is counted in the bar to the right.

 

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