COMM 291 Study Guide - Final Guide: Total Variation, Analysis Of Variance, Statistical Significance
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COMM 291 Full Course Notes
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Variances are equal & sample size is small (independent means) Jb"s rule of thumb: we can safely assume that 1 larger s is not much more than twice the smaller s. Excel n1 t = ( x1 x2) 0. X2 ) = s1 ( x1 x2 ) t*df s1 n1. Ho: 1 2 = 0 or ho: 1 = 2. Ha: 1 2 />/< 0 or ha: 1. Difference between the two means; if one mean is greater than the other/if the means are equal. Data on the same cases in 2 different circumstances (dependent. Independence assumption: randomized condition, 10% condition (don"t sample >10% of population) Normal population assumption: nearly normal condition. P-value = 2 x pr (t >| t-stat|) There is no difference between the two means; the difference is greater than 0. When comparing times (ie. spending in january vs. february) Counted data condition (two categorical: independence, randomization condition, sample size assumption.
