What to do 
What you see 
1) Press the [2nd][STAT] key. Note: To type [2nd][STAT], press the [2nd] key, then find STAT above the [MATRX] key, and press that key.  CALC
DRAW DATA
1:1Var 2:LinReg 3:LnReg 4:ExpReg 5:PwrReg 
2) Now press the key twice to highlight the word DATA on the top line of the screen. Note how the menu options change:  CALC DRAW DATA
1:Edit 2:ClrStat 3:xSort 4:ySort 
3) Press [2][ENTER] to select "ClrStat" and clear any previously entered data.  ClrStat
Done 
4) Press [2nd][STAT]again and to get back to the screen in step 2:  CALC DRAW DATA
1:Edit 2:ClrStat 3:xSort 4:ySort 
5) Now press [1] to select EDIT and begin entering data.  DATA
x1=_ y1=1 
4) Enter your list of numbers one at a time after
the x's. A "1" will automatically appear after the y's.
For instance, to enter the list 1,3,5, type [1][ENTER][ENTER]
[3][ENTER][ENTER] [5][ENTER][ENTER]

DATA
x1=1 y1=1 x2=3 y2=1 x3=5 y3=1 
5) Now, to compute some statistics, press [2nd][STAT] to go to the statistics screen, [1] to select 1Var statistics, and [ENTER] to compute those statistics.  1Var
=3 x=9 x^{2}=35 Sx=2 x=1.632993162 n=3 
6) The =3 tells you the mean of your list is 4. The x=1.63299... tells you the [population] standard deviation of your list is 1.63299.... 
data item  frequency 








...meaning that your list contains four 3's, five 8's, etc., then you
can enter the data items as x's and the corresponding frequencies as y's
on the EDIT screen. For this list, you would enter
DATA
x1=3 y1=4 x2=8 y2=5 x3=1 y3=7 
...etc.