Interprete Minitab Output for One-Way ANOVA

Hypothesis for this example:

H0 : μ1 =  μ2 =  μ3

H1 : At least one mean is different from the others.

Interpretation:

It can be said that the concentration of Mercury in the three regions is different. This indicates that there are different sources of pollution that affect the three regions. It could be due to different activities operating in each region.

Check out the multiple comparison here.

Type I and Type II Errors

There are four possible outcomes in the hypothesis testing situation. The four possible outcomes are shown in the figure above. There are two possibilities for a correct decision and two possibilities for a wrong decision.

Correct decision happens when

• H0 is false and it is rejected (This is our target)
• H0 is true and it is not rejected

Incorrect decision happens when

• H0 is false and it is not rejected
• H0 is true and it is rejected (We must reduce this error)