area under the curve

A student wants to know how one can calculate the area under the curve for skewed distributions.  Can someone give me an answer about when a distribution is too skewed to use the z table?   Melady

Introductory Statistics text

I am looking for a new and improved Statistics text for an introductory (3rd year) stats course for psychology majors...I would welcome any suggestions/reviews, etc. Melady Preece = Instructions for joining and leaving this list

Comparing percent correct to correct by chance

Hi. I want to compare the percentage of correct identifications (taste test) to the percentage that would be correct by chance 50%? (only two items being tasted). Can I use a t-test to compare the percentages? What would I use for the s.d. for by chance percentage? (0?) Melady - Origina

Categorical data Take 2

eer and no change into number of hours involved in productive activity.  That would give be three outcomes.   Any suggestions would be much appreciated!   Melady Preece, Ph.D.  

Interpreting effect size.

, and .33 if I divide by the pooled standard deviation. Question 1: Which is the correct standard deviation to use? Question 2: Can an effect size of .29 (or .33) be considered clinically significant? Melady Preece, Ph.D