Geometric mean and std. dev. on 12C or 12CP  Printable Version + HP Forums (https://archived.hpcalc.org/museumforum) + Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum1.html) + Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum2.html) + Thread: Geometric mean and std. dev. on 12C or 12CP (/thread104084.html) 
Geometric mean and std. dev. on 12C or 12CP  mk  12112006 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?
Re: Geometric mean and std. dev. on 12C or 12CP  Norris  12112006 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 sigmaplus key, you could substitute a simple programmed function that would first calculate the natural log, then enter the logtransformed value into the stats registers via sigmaplus.
When all of the logtransformed values had been entered, you could calculate the mean or s.d. of the logtranformed values as usual. Then take the antilogs to get the geometric mean or geometric deviation.
Re: Geometric mean and std. dev. on 12C or 12CP  Katie Wasserman  12122006 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 rekeying them in. Entering them as cash flows is just as easy as using Sigma+.
