Find the mean and spread of one list

Get the count, sum, mean and standard deviation of a list of numbers in one go.

One-variable statistics describe a single list with a handful of numbers: how many values there are (n), their sum, their mean and how spread out they are.

The example list is 2, 4, 6, 8, 10. Its mean is 6 and its sample standard deviation is about 3.1623.

RPN models work differently: you press the sum key after every value, then ask for the mean and the spread.

Classic Graphing 84

Start on the main screen: Press 2nd then mode (QUIT) to get back to the home screen. Pressing clear on a menu also backs out of it.

Type the five numbers into list L1.
stat12enter4enter6enter8enter10enter
Open the STAT menu, move to CALC and pick 1-Var Stats.
stat▶1
The list is already L1. Move down to Calculate and press enter.
▼▼enter

You should seeThe screen lists x̄ (mean), Σx, Σx², Sx, σx and n. Scroll down for the minimum, quartiles and maximum.

Classic Graphing 84 key reference

Classic Scientific 30

Start on the main screen: Press 2nd then mode (QUIT) to leave any menu or screen and return to the calculation screen.

Type the five numbers into list L1.
data2enter4enter6enter8enter10enter
Press 2nd then data for the STAT menu and choose 1-Var Stats.
2ndstatdata1enter
Press enter to calculate. Use the down arrow to see more results.
enter

You should see1:n=5 2:x̄=6 3:Sx=3.16227766

Classic Scientific 30 key reference

Natural Scientific 991

Start on the main screen: Press MENU, then 1 (Calculate) to return to the main calculation screen. AC clears the line you are on.

Open Statistics and choose 1-Variable, then type the numbers.
MENU612=4=6=8=10=AC
Press OPTN and choose 1-Variable Calc.
OPTN3

You should seeUse the down arrow to reach σx, sx, n and the quartiles.

Natural Scientific 991 key reference

Natural Color Graphing

Start on the main screen: Press MENU then 1 to open Run-Matrix, the main calculation screen. Press EXIT to back out of a bar or screen, and SHIFT then EXIT (QUIT) to return to the app start.

Enter the numbers in List 1 of the Stat mode.
MENU22EXE4EXE6EXE8EXE10EXE
Choose CALC (F2), then 1-VAR (F1).
F2F1

You should seex̄=6 Σx=30 σx=2.828427125 sx=3.16227766

Natural Color Graphing key reference

RPN Scientific 15

Start on the main screen: There is no menu to leave. Press the back arrow to clear a number you are typing, or CLx (g then back arrow) to clear the X register.

Clear the statistics memory first, so old data cannot sneak into the answer.
fCLR ΣGSB
Key in each number and press Σ+. The display counts how many you have added.
2Σ+4Σ+6Σ+8Σ+10Σ+
Press g then 0 for the mean (x̄).
gx̄0
Press g then the decimal point key for the sample standard deviation (s).
gs.

You should seeThe mean (6.0000) sits one level up the stack, and s is 3.1623.

RPN Scientific 15 key reference

RPN Financial 12

Start on the main screen: There is no menu to leave: the display always shows the X register. Press f then R/S (P/R) to leave program mode, and clear a pending prefix by pressing ON.

Clear the statistics registers with f then CLx.
fREGCLx
Key in each number and press Σ+.
2Σ+4Σ+6Σ+8Σ+10Σ+
Press g then 0 for the mean, then g then the decimal point for the standard deviation.
gx̄0gs.

You should see6.00 3.16

RPN Financial 12 key reference

RPN Advanced 42

Start on the main screen: Press EXIT (once or twice) to close any menu and return to the plain stack view of Y and X.

Key in each number and press the Σ+ key (the top-left key).
2Σ+4Σ+6Σ+8Σ+10Σ+
Open the STAT menu with shift then the ÷ key. The menu keys along the top are now Σ+, SUM, x̄, x̄w, s and FIT.
⇧STAT÷
Press the third menu key for the mean.
√x

You should see6.0000

Press the fifth menu key (s) for the sample standard deviation, 3.1623.

RPN Advanced 42 key reference

Tips

Two spread numbers are shown: Sx is the sample standard deviation and σx is the population one. Use Sx unless your data is the whole group.
Leftover data is a common reason for a wrong n. Clear old lists or statistics memory before starting.