The Bonferroni procedure can be used in multiple comparison to determine which means differ. Using a sample set of data below with three groups of equal size data, the ANOVA 2-way function is calculated and the results stored in **stat1**. For convenience, the standard ANOVA is also calculated and the results stored in **stat6**.

The original confidence level is set to 0.05. To obtain the corrected confidence level value, 0.05 is divided by the number of group of data, and then by 2 for 2-tail test. The new critical t-value is then determined. The means for each group is available in the **stat6** variable set (by ANOVA), while the pooled standard deviation s can be obtained from **stat1** variable set (by ANOVA 2-way).

And then for each of the combination of group, calculate its new t-value, i.e. GA-GC, GB-GC, and GA-GB respectively.

As shown above, the combination of GA-GB is less than the critical value of 2.7178, meaning that **fail to reject H_{0}** and therefore can conclude that

**μ**.

_{A}=μ_{B}