formulas - FORMULAS Sociology 549, Paul von Hippel...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
FORMULAS Sociology 549, Paul von Hippel Descriptive statistics Measures of center 1. mode 2. median 3. trimmed mean 4. mean N Y Y = or, for a frequency table, N fY Y = For a dummy variable the mean is p , the proportion of observations with a value of Y =1. Measures of variation 1. range 2. interquartile range 3. variance 1 ) ( 2 2 = N Y Y S Y or, for a frequency table, 1 ) ( 2 2 = N Y Y f S Y 4. standard deviation 2 Y Y S S = For a dummy variable the variance is and the standard deviation is ) 1 ( p p ) 1 ( p p Standard ( z ) scores Y S Y Y Z = Y ZS Y Y + = Inferential statistics One mean True standard error N Y Y / σ = Estimated standard error N S S Y Y / = Confidence interval Y tS Y ± , df = N -1 Test statistic Y Y S Y t µ = , df = N -1 One proportion True standard error N p / ) 1 ( π = Estimated standard error N p p S p / ) 1 ( = Confidence interval p zS p ± Test statistic p p z =
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Difference between two means
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This document was uploaded on 06/01/2011.

Page1 / 2

formulas - FORMULAS Sociology 549, Paul von Hippel...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online