The position of the graphically represented keys can be found by moving your mouse on top of the graphic. 
The rounded bullet shaped keys on top do not count as rows.

Turn your calculator on
Press The ON C Key: Red bullet shaped key on upper right side..
Clearing the memory
The memory is automatically cleared when you leave the STAT mode.

 

Entering data
one variable
Press The Second F Key: Blue bullet shaped key on upper left side. The Hyp Key: Row 1, Column 4 (You should see STAT above the key. STAT will also appear on the screen.) Press The M Plus Key: Row 8, Column 1 and enter the first number in your list. Enter the other numbers in your list, pressing The M Plus Key: Row 8, Column 1 before each one. (Note that this is opposite the usual order.)
two variables
The HP 9s does not do regression.

 

Calculating one-variable statistics
mean (x)
Press The X arrow M Key: Row 6, Column 1. You should see x above the key on the left.
standard deviation for populations (s or sn)
Press The Second F Key: Blue bullet shaped key on upper left side. . You should see s in a box above the key.
standard deviation for samples (s or sn-1)
Press . You should see s above the key.

Calculating two-variable statistics
r (correlation)
The HP 9s does not do regression.
regression coefficients
slope
The HP 9s does not do regression.
y-intercept
The HP 9s does not do regression.


Calculating combinations and permutations
combinations (nCr)
Enter n. Press The Second F Key: Blue bullet shaped key on upper left side. The Seven Key: Row 4, Column 2 (you should see nCr above the key). Enter r and press The Enter Key: Row 8, Column 5.
permutations (nPr)
Enter n. Press The Second F Key: Blue bullet shaped key on upper left side. The Eight Key: Row 4, Column 3 (you should see nPr above the key). Enter r and press The Enter Key: Row 8, Column 5.

 

Turning the calculator off
Press The Second F Key: Blue bullet shaped key on upper left side. The ON C Key: Red bullet shaped key on upper right side..

 

Worked Out Examples

In the following examples, we list the exact key sequence used to find the answer.  We will list the keys by the main symbol on the key.  In parentheses, we will list a helpful mnemonic, e.g. we will list ex as (ex).


A: What is the mean and standard deviation of the following list of numbers?

15      16      20      21

1: Clear Memory   
2: Enter Data  The Second F Key: Blue bullet shaped key on upper left side. The Hyp Key: Row 1, Column 4 (STAT) The M Plus Key: Row 8, Column 1 The One Key: Row 7, Column 2 The Five Key: Row 5, Column 3 The M Plus Key: Row 8, Column 1 The One Key: Row 7, Column 2 The Six Key: Row 5, Column 4 The M Plus Key: Row 8, Column 1 The Two Key: Row 7, Column 3 The Zero Key: Row 8, Column 2 The M Plus Key: Row 8, Column 1 The Two Key: Row 7, Column 3 The One Key: Row 7, Column 2 
3: Compute the mean  The X arrow M Key: Row 6, Column 1 ( x )
4: Compute the population standard deviation  The Second F Key: Blue bullet shaped key on upper left side.  (s) 
5: Compute the sample standard deviation   (s)


    You should get a mean of 18, population standard deviation of 2.549509757 and a sample standard deviation of 2.943920289.

C: Find 10C6 and 9P5.
1:Compute 10C6

 The One Key: Row 7, Column 2 The Zero Key: Row 8, Column 2 The Second F Key: Blue bullet shaped key on upper left side. The Seven Key: Row 4, Column 2 The Six Key: Row 5, Column 4 (nCr) The Enter Key: Row 8, Column 5
2: Compute 9P5  The Nine Key: Row 9, Column 4 The Second F Key: Blue bullet shaped key on upper left side. The Eight Key: Row 4, Column 3 The Five Key: Row 5, Column 3 (nPr) The Enter Key: Row 8, Column 5


You should get 10C6 = 210 and 9P5= 15120.

Go to: 

HP's statistics manual
HP's online manual		 sample problem set Home page