Re: Basic normal and t table questions

*To*: mathgroup at smc.vnet.net*Subject*: [mg110061] Re: Basic normal and t table questions*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Sun, 30 May 2010 23:48:14 -0400 (EDT)

Use InverseCDF dist = NormalDistribution[187000, 2181.9716]; 1 - CDF[dist, 190000] 0.0845807 InverseCDF[dist, 1 - %] 190000. Needs["HypothesisTesting`"] StudentTPValue[-0.1373, 6, TwoSided -> True] TwoSidedPValue->0.895285 InverseCDF[StudentTDistribution[6], (1 - TwoSidedPValue/2) /. %] 0.1373 Since it is two-sided, the sign is meaningless Bob Hanlon ---- Canopus56 <canopus56 at yahoo.com> wrote: ============= I am taking an intro to stats class and am trying to learn some Mathematica functions related to basic statistics. I would like to use Mathematica to calculate exact values and inverse values from the standard normal table and Student's t distribution table. For example, the following returns the cdf equvialent to standard normal distribution table for a known mu, sigma (STD) and target x-bar: (1 - CDF[NormalDistribution[187000, 2181.9716], 190000]) The following returns the two-sided t-distribution value for a known z-statistic: StudentTPValue[-0.1373, 6, TwoSided -> True] Q1) How do I get the inverse of these, which the equivalent of reading a cdf table and a t-distribution table backwards, i.e. - a) Given a cdf, how do I return the z-statistic from a standard normal distribution? b) Given a P-Value and sampling distribution size, how did I return the z-star critical test value? Thanks - Kurt