One Variable Statistics

Consider the following frequency distribution for grouped data:

Class	Frequency	Midpoint
5.5 - 10.5	1	8
10.5 - 15.5	2	13
15.5 - 20.5	3	18
20.5 - 25.5	5	23
25.5 - 30.5	4	28
30.5 - 30.5	3	33
30.5 - 40.5	2	38

The ONE VARIABLE STATISTICS option provides summary information on a frequency distribution of grouped data. Specifically, the following information is provided:

	the mean or average
	the sum of all data
	the sum of the squares
	the sample standard deviation
	the population standard deviation
	the number of elements
	the minimum element
	the first quartile
	the median of the data
	the third quartile
	the maximum element

First enter the midpoints into and frequencies into . To learn how to enter data into a list, go to Making a Table . Once the data are entered, the screen should appear as shown below:

Next, press STAT and then press the RIGHT ARROW to get to the CALC menu. Select 1-Var STATS by pressing ENTER. Make sure L₁ listed for List: the pre ENTER to FreqList: and press 2nd 2 to type L₂. Press ENTER twice.

After pressing ENTER again, the final screen should appear as shown below:

The located at the bottom left of the screen indicates that there are more entries to be displayed. By pressing the DOWN ARROW key, the other ONE VARIABLE STATISTICS are displayed.