**HP 11C (and Emulators): The Four Means**

**Introduction**

The following program uses the statistical registers to calculate four types of mean:

Arithmetic Mean: μ = Σx / n

Harmonic Mean: HM = n / Σ(1/x)

Geometric Mean: GM = (Πx) ^ (1/n)

Root Mean Square: RMS = √(Σx^2 / n)

The HP 11C uses the following registers in statistical analysis. Be sure to clear registers by pressing [ f ] [ x<>y ] (CLEAR REG) before beginning. **Also, after clearing the registers, store 1 in register 7 (R7). **

R0 = n

R1 = Σx

R2 = Σx^2

R3 = Σy

R4 = Σy^2

R5 = Σxy

LBL A: Enter data

LBL B: Analysis: μ [R/S], HM [R/S], GM [R/S], RMS

**HP 11C Program: The Four Means**

Don’t forget to store 1 in R7 prior to running the program.

001 42, 21, 11 LBL A

002 49 Σ+

003 43, 36 LAST x

004 44, 20, 7 STO× 7

005 15 1/x

006 44, 40, 6 STO+ 6

007 43, 32 RTN

008 42, 21, 12 LBL B

009 43, 0 x-bar

010 32 R/S

011 45, 6 RCL 6

012 15 1/x

013 45, 0 RCL 0

014 20 *

015 31 R/S

016 45, 7 RCL 7

017 45, 0 RCL 0

018 15 1/x

019 14 y^x

020 31 R/S

021 45, 2 RCL 2

022 45, 0 RCL 0

023 10 ÷

024 11 √

025 43, 32 RTN

Example:

Sample set: 4.25, 4.08, 5.63, 6.13, 4.48, 7.02 ( 6 data points )

Keystrokes:

4.25 [ f ] [ √ ] (A)

4.08 [ f ] [ √ ] (A)

5.63 [ f ] [ √ ] (A)

6.13 [ f ] [ √ ] (A)

4.48 [ f ] [ √ ] (A)

7.02 [ f ] [ √ ] (A)

[ f ] [e^x] (B) 5.2650 (arithmetic mean, μ)

[R/S] 5.0556 (harmonic mean, HM)

[R/S] 5.1575 (geometric mean, GM)

[R/S] 5.3748 (root mean square, RMS)

Eddie

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