This chapter helps compare two or more populations of interval data. Determines whether differences exist between populations means. Anova tests to determine whether differences exist between two or more population means. If null hypothesis is true, population means would all be equal; h0 is always states that there is no difference between the means. H1 always says at least two means differ. Within-treatments variation or sse: is not cause by the treatments measures amount of variation in the response variable that: group all sources of variation and call them errors. This variation is measured by sum of squares for error (sse: sse is a combined or pooled variation of k samples. Sse measures variation within the samples: the population variances must equal. The test statistic is f distributed with k 1 and n k degrees of freedom. When finding mst and mse, we compute unbiased estimators of common population variance, assuming that null hypothesis is true.