We use the ANOVA (Analysis of Variance) aka F-Test when comparing the means of three or more groups.
One-Way ANOVA
A one-way ANOVA has one dependent variable and only one independent variable (or factor).
A one-way ANOVA has two hypotheses:
H (null): μ = μ = μ
H (alternative): at least one of the means are not equal.
Example.
Two-Way ANOVA
A two-way ANOVA has one dependent variable and two independent variables (factors).
A two-way ANOVA has three null and alternative hypotheses:
H (null): No relationship between Dependent variable and Factor A
H (null): No relationship between Dependent variable and Factor A
H (null): No interaction between Factor A and Factor B
H (alternative): Relationship between Dependent variable and Factor A
H (alternative): Relationship between Dependent variable and Factor B
H (alternative): Interaction between Factor A and Factor B
Examples
Calculators
The easiest way to calculate a z score, and find it's probability (p-value) is to use a statistics calculator.
Graphing calculators, statistical software programs (such as Excel, SPSS, R), or free online calculators are all able to Z-Tests, which give you the z-score and resulting probability for a value in a dataset.
Next, let's take a break - and then learn more about populations, samples, and hypothesis testing.
Contact us for practice materials regarding standard deviation, the bell curve, the empirical rule, normal probability, and more.
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