# Lecture 12.docx - October 31 2022 Analysis part 2 T-test ●...

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October 31, 2022Analysis part 2T-testT distribution2 groupsAnovaMore than 2 groupsVarianceSum of squares(n-1) vs nSample is the population divide by nWhen it is not use (n-1)Why variance?Cannot distinguish groups based on just the mean, need to use variance as well
October 31, 2022Degrees of FreedomHow many values in a data set can be variedmean= sum of the outcomes/ the total number of outcomes5 variables that are free to varyF StatisticF refers to FisherRatio of mean square among groups to the mean square within groupsMean squares= sum of squares/ degrees of freedomAnova ‘Ingredients’At least 3 groupsSum of squares among groups
October 31, 2022Dispersion within each group compared to the dispersion among each groupAnova Example4 groups, is there a difference among the groupsYi: any of the groups, average value of each groupNi: sample sizesAnova tells us if there is a greater different within or among each groupGrand MeanSum of all the values divided by the total sample sizeSum of Squares Among groupsAverage value subtract the grand mean and square it and multiply by the sample

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Term
Fall
Professor
N/A
Tags
Null hypothesis, Statistical hypothesis testing