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Comparing Multiple Means: Analysis of Variance

Introduction

A student's T-test can be used to compare two samples. Often, it is necessary to compare more than two samples. Analysis of variance (ANOVA) is a powerful statistical analysis tool that can be used to compare the mean of three or more populations efficiently. An interesting fact to remember is that the analysis of variance actually compares the means. In ANOVA, variation is partitioned using the sum of squares. This statistical analysis tool is used to test hypotheses about differences between two or more means. The null hypothesis in ANOVA can be stated as:

 

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Alternate hypothesis ...

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