Geometric mean and std. dev. on 12C or 12CP



#4

The 12C is great for easily calculating a standard deviation on a list of numbers, using the standard deviation key and the statistics keys (sigma +).

But is it possible to get the geometric mean from the HP 12c or 12cp from the same accumulated statistics without rekeying them all or entering a separate program?


#5

I doubt it.

It is possible to calculate the geometric mean, if you have the product of all the entered values. However, the 12C calculates and stores the summation of the entered values, not the product.

In theory, it should not be difficult to calculate geometric means and geometric deviations on the 12C. Instead of the sigma-plus key, you could substitute a simple programmed function that would first calculate the natural log, then enter the log-transformed value into the stats registers via sigma-plus.

When all of the log-transformed values had been entered, you could calculate the mean or s.d. of the log-tranformed values as usual. Then take the antilogs to get the geometric mean or geometric deviation.

#6

The 12CP allows for 80 cash flow numbers that are accessible as an array of sorts. It would be simple to write a program to calculate the geometric mean/sd of them. You could also compute the arithmetic mean/sd of them without re-keying them in. Entering them as cash flows is just as easy as using Sigma+.


Possibly Related Threads...
Thread Author Replies Views Last Post
  [WP34S] WP34S firmware on the AT91SAM7L-STK dev kit? jerome ibanes 1 425 10-04-2012, 04:59 PM
Last Post: Paul Dale
  38E/C, 12C, 12CP date arithmetic bug Katie Wasserman 26 1,821 10-19-2011, 08:57 PM
Last Post: Miguel Toro
  HP 12C, 12C Platinum & 15C iOS App Walter Lam 2 479 06-02-2011, 01:25 PM
Last Post: Andrés C. Rodríguez (Argentina)
  12c+ vs 12cp Erturk Kocalar 7 664 03-08-2011, 11:32 AM
Last Post: Marcus von Cube, Germany
  ADV or STD HEPAX? Diego Diaz 7 760 07-31-2010, 11:27 AM
Last Post: Diego Diaz
  10bII, 12c, 12cp, 17b2+ ... these are the ones I see...Poll...how about you? Gene Wright 23 1,818 05-30-2010, 09:14 AM
Last Post: Don Shepherd
  Gamma (and Factorial) for 12C/12CP Les Wright 9 897 02-02-2009, 06:18 PM
Last Post: Egan Ford
  Gamma and Factorial for 10C/12C/12CP (thread hijack) Les Wright 1 389 01-28-2009, 08:19 PM
Last Post: Egan Ford
  HP-20B dev: LCD Scott Newell 0 279 07-22-2008, 12:48 AM
Last Post: Scott Newell
  Received new 12CP Anniversary Edition today, but... Stephen Easterling 6 695 04-22-2008, 12:28 PM
Last Post: Stephen Easterling

Forum Jump: