Answer
The results are ambiguous. We can conclude that $µ_1\neµ_2$, for example, but we could not conclude that $µ_1\neµ_4$ or $µ_4\neµ_2$. There is at least one Type II error (when we do not reject $H_0$ when we should have rejected).
Work Step by Step
In MINITAB, enter the Brand 1 values in C1, the Brand 2 values in C2, the Brand 3 values in C3, the Brand 4 values in C4, the Brand 5 values in C5 and in C6 enter the Brand 6 values.
Select Stat -> ANOVA -> One-Way
Select Response data are in a separate column for each factor level.
In Responses enter C1 C2 C3 C4 C5 C6
Click Comparisons. In "Error rate for comparisons" enter 5. In "Comparison procedures assuming equal variances" select Tukey. In "Results" select the 3 options. Click OK.
Click Ok.
