When I insert the statistical data in my Casio FX9750GII Graphic Calculator it gives out inaccurate value of mean and standard deviation. What should I do?

Z-score=(X-mu)/(sigma_d)
(X-value - mean value)/(standard deviation)

It depends what the two list mean.
If you are doing 1-var statistics you may want to enter the frequency of a data element (if some are repeated) in the list L2.
In that case when you run the CALC 1-Var , you first press the F6 key to set the lists Data List1, and Frequency List 2.
Once you set the lists, press the F1 key to select 1-var. The calculator will give all the statistics of the distribution.

If you are doing 2-var stats SET the lists and press F2 2-var. The calculator will give you the x-statistics, followed by the y-statistics.

Here are the capabilities of the calculator.
In stat enter the values in List1 and the frequencies in List2
Press the key corresponding to the CALC tab



Press the 1-var tab and you get the results as seen on the screen with title 1-variable.
Other screens show some two-varaible stats or regressions.

This will show you how to do statistics (calculate average, standard deviation, regressions etc.) as to the mode and median refer to the definitions.

TO COMPUTE STANDARD DEVIATION AND 2-VAR STATISTICS.

I assume you know the theory. I will show you the key strokes

For 1-Var statistics
Press [MODE][3:STAT] [1:1-VAR]. You are ready to enter values in the X column.
Enter a number and press [=]. Cursor jumps to second number to enter.
Keep entering numbers and pressing [=] till all numbers are in. Press the [=] key after the last one.
Press [AC] key to clear the screen.
Press [SHIFT] [STAT] (above digit 1.) then [5:Var]. Screen displays the statistical variables 1:n ;2: x bar; 3: x sigma n; 4:x sigma n-1.
Press the number corresponding to the statistical value you want, ex 1:n . The variable appears on screen. Press [=] and it will be displayed.
To display another variable press [SHIFT][STAT][5:Var][ 1,2, 3, or 4] .

To access the sum of squares sigma x^2 and the sum of data sigma x press[SHIFT][STAT][4:SUM] then [1: for sigma x^2] or [2: for sigma x]. Press [SHIFT][STAT][6:MinMax] to access minX and maxX.

For 2-var statistics
To perform 2 variable statistics you press [MODE][3:STAT] and any of the other regression options (except 1:1-Var). A two column template opens where you enter the X and Y values. When finished entering data, press [SHIFT][STAT][5:Var]. to access the different statistics. As I assumed above, you should be able to recognize what each variable means.

Press 2nd [STAT] then select CLRDATA to clear statistics data. Select 1-VAR or 2-VAR for one-variable or two-variable statistics. Press DATA and enter your data (x for 1-VAR or x and y for 2-VAR). Press 2nd [EXIT-STAT] and select N. Press STAT-VAR to see a menu of statistics variables and their values. Sx (and Sy) will give you the standard deviation, sigma-x (and sigma-y) will give you the population standard deviation.

first off you want you calculator in SD (standard deviation) mode to do this hit mode twice and then 1.
next it is good practice to start off by clearing the memory to do this hit shift, CLR,1 and then = this will clear statistical memory
to enter values into your data set , you enter the value, then press the DT (M+) button. (note: pressing DT repeatedly will impute the same value multiple times)
once you have finished pluging in your numbers your calculator can give you statistical information about the data set.
hitting shift then 1(S-SUM) gives you three options: 1 the sum of the squares of each value 2 the sum of each value 3 the number of terms in the data set hitting shift then 2 (S-VAR) gives you three more options 1 x bar (the mean) 2 x sigma n (the population standard deviation) 3 x sigma n-1 (the sample standard deviation)
you can use these tools to solve alot of statistical problems i hope this helped
Source: http://support.casio.com/pdf/004/fx115MS_991MS_E.pdf page 28 of he pdf

The variance is the square of the standard variation

TO COMPUTE STANDARD DEVIATION AND 2-VAR STATISTICS.

I assume you know the theory. I will show you the key strokes

for 1-Var statistics
Press [MODE][3:STAT] [1:1-VAR]. You are ready to enter values in the X column.
Enter a number and press [=]. Cursor jumps to second number to enter.
Keep entering numbers and pressing [=] till all numbers are in. Press the [=] key after the last one.
Press [AC] key to clear the screen.
Press [SHIFT] [STAT] (above digit 1.) then [5:Var]. Screen displays the statistical variables 1:n ;2: x bar; 3: x sigma n; 4:x sigma n-1.
Press the number corresponding to the statistical value you want, ex 1:n . The variable appears on screen. Press [=] and it will be displayed.
To display another variable press [SHIFT][STAT][5:Var][ 1,2, 3, or 4] .

To access the sum of squares sigma x^2 and the sum of data sigma x press[SHIFT][STAT][4:SUM] then [1: for sigma x^2] or [2: for sigma x]. Press [SHIFT][STAT][6:MinMax] to access minX and maxX.

For 2-var statistics
To perform 2 variable statistics you press [MODE][3:STAT] and any of the other regression options (except 1:1-Var). A two column template opens where you enter the X and Y values. When finished entering data, press [SHIFT][STAT][5:Var]. to access the different statistics. As I assumed above, you should be able to recognize what each variable means.

Hello,
Set the [Mode] to [3:STAT]. You are offered the choices
1:1-Var
2:A+BX
3:__+cX^2
etc.
If you want to do 1-Var statistics, you press 1:1-Var. A column template opens where you put the X values. If a value is repeated you enter it several times. (there is no frequency column.)
When you enter all data you press [SHIFT][STAT]

You have several choices among them
4: SUM to get SigmaX^2 and Sigma X
5: VAR to get n, the mean X bar, the sample and population standard deviations
6:MINIMAX to get MinX and MaxX
7: Distr the Distributions.

If you want to perform 2-Var statistics
You press [MODE][STAT] and select one of the Regression models
2:A+BX
3:__+cX^2
etc.
The selection of any of the 7 regression models, opens a two-column template where you enter the X and Y values
When finished press [SHIFT][STAT]
The choices offered are

1. Type takes you back to select type of statistics to perform
   
2. Data To edit the data in the columns
   
3. Edit To insert or delete a value
   
4. SUM To access the calculated values of SigX^2,SigX,SigY^2,SigY,SigXY,SigX^3, SigX^2Y, SigX^4
   
5. Var : To access the calculated values n, Xbar, Sample STD for x, S STD for Y, Pop STD for X, and Pop STD for Y
   
6. MinMax : MinX, MinY, MaxX, MaxY
   
7. Reg: Gives you the regression coefficients for the particular regression model you want to test.

The mean is represented by X bar.
The variance is the SQUARE of the Standard Deviation.
Hope it helps.

Hello,

In the main menu select [STAT] icon to enter Stat mode and display the statistical data lists. Use the satistical data lists to input data and perform statistical calculations. Use the arrows to move the highlighting around the lists.
Exemple: Enter the following values in List 1
1st line enter 90 [EXE]
2nd line 85 [EXE]
3 79 [EXE]
4 75 [EXE]
5 70 [EXE]
6 68 [EXE]
7 56 [EXE]

When finished you press [F2:Calc], then [F1:1Var] and the statistical results appear on screen.
Title of screen : 1-Variable
x bar =74.7142857
Capital Sigma x= 523
Capita Sigma X squared = 39851
x lower case sigma n = 10.5249945
x lower case sigma n-1= 11.3682934
n = 7
Scroll down with Down arrow to access other data
minX =56
Q1=68
Med =75
Q3=85
Xbar -x lower case sigma n =64.1892911
x bar + x lower case sigma n = 85.2392802
maxX=90
Mod=90

All you have to do now, is to look at the theory you learned and interpret what these values mean.

Hope it helps.

standard deviation

calculate mean of a data set:

1. Turn calc. on or press MODE SeTUP
2.Press 3 for STAT
3. Press 1 for VAR
4.Enter values for X column
5. WHen done entering press SHIFT 1
6.Press 5
7.Press 2 to calculate the mean
8.Press =