The position of the graphically represented keys can be found by moving your mouse on top of the graphic.
Turn your calculator on  
Press .  
Clearing the memory  
Turn the calculator off, then on again. (That is, press ) 
Entering data  
one variable  
Enter the first number, then press . The screen will now say n=1 indicating that you have entered one data point. Enter the second number, press . The screen will now say n=2 because you have entered two data points. Continue until all the data has been entered.  
two variables  
The TI30Xa does not do regression. 
Calculating onevariable statistics  
mean (x)  
Press (you should see x above the key).  
standard deviation for populations (s or s_{n})  
Press (you should see s_{xn} above the division sign).  
standard deviation for samples (s or s_{n1})  
Press (you should see s_{xn1}above the square root sign). 
Calculating twovariable statistics 

r (correlation)  
The TI30Xa does not do regression.  
regression coefficients  
slope  
The TI30Xa does not do regression.  
yintercept  
The TI30Xa does not do regression. 
Calculating combinations and permutations  
combinations (nCr)  
Enter the n value. Press
(you
should see double arrows above the pi key), then the r value. Then press
(you should see nCr over the 8 key).
Curiously, there is a second way. Enter the n value. Press . Enter the r value. Press . We have no idea why this works. 

permutations (nPr)  
Enter the n value. Press
(you
should see double arrows above the pi key), then the r value. Then press
(you should see nPr over the 9 key).
Curiously, there is a second way. Enter the n value. Press . Enter the r value. Press . We have no idea why this works. 
Turning the calculator off  
Press . 
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 e^{x} as (e^{x}).
A: What is the mean and standard deviation of the following list of numbers?
15 16 20 21
1: Clear Memory  
2: Enter Data 

3: Compute the mean  (x) 
4: Compute the standard deviation (population)  (s_{xn}) 
5: Compute the standard deviation (sample)  (s_{xn1}) 
You should get a mean of 18, population standard deviation of
2.549509757 and a sample standard deviation
of 2.943920289.
1: Compute _{10}C_{6}  (_{n}C_{r}) 
2: Compute _{9}P_{5}  (nPr) 
You should get _{10}C_{6 }= 210 and _{9}P_{5}=
15120.
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