Re: Draw approximated normal distribution based on mean, median, percentiles?
- To: mathgroup at smc.vnet.net
- Subject: [mg70130] Re: Draw approximated normal distribution based on mean, median, percentiles?
- From: "ben" <benjamin.friedrich at gmail.com>
- Date: Thu, 5 Oct 2006 03:32:21 -0400 (EDT)
- References: <firstname.lastname@example.org>
Hi Richard, the point is that your age distribution probably is not normal distributed, otherwise mean and sdv would be sufficient to pin it down. Now there's an infinite variety of distribution functions out there, even with fixed percentiles and median. What you need is some kind of model for your distribution function with some free parameters. What is normally used in the literature? Then one could use mathematica to get hold of these free parameters by using the percentille, sdv, etc information provided. Bye Ben rflaaten at start.no schrieb: > Hello all, > > I searched the forum for any info on this, so here goes. > > I need to reference some statistical data from a study. The information > given there for an age distribution is: mean, standard deviation, > median plus the 25th and 75th percentiles. Now, I have tried in vain to > get Excel or SPSS to draw this for me. Is there any way of inputting > percentiles and median into Mathematica? The normal distribution > function only takes mean and sd as far as I know. > > > Any help would be much appreciated. > Richard