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Analysis of Variance (ANOVA). ANOVA data. Grand Mean = 4.375. Independent t-test. Variance. ANOVA data. Grand Mean = 4.375. Variance. total variance = within groups variance + between groups variance. May Affect Number of Headaches. genetics stress diet gender sleep … new drug.
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ANOVA data Grand Mean = 4.375
ANOVA data Grand Mean = 4.375
Variance total variance = within groups variance + between groups variance
May Affect Number of Headaches • genetics • stress • diet • gender • sleep • … • new drug Error --- IV
ANOVA data IV (drug) error
Between-group var = IV + error • Within-group var = error • F = between var / within var = • (IV+error) / error • If IV has no effect, F = error/error = 1 • Is F significantly greater than 1?