Question

1. Braking distance was evaluated for 4 different brake materials. Run an analysis of variance to determine if there is a difference in treatments?   Use the six steps of hypothesis testing at a 0.05 level of significance. Put the below data into Excel to perform the analysis.

Braking Distance
Disk Material 1	Disk Material 2	Disk Material 3	Disk Material 4
69.8	78.1	77.7	90.6
65.6	81.0	80.9	91.0
71.7	81.9	80.8	89.4
70.5	81.8	79.8	88.1
68.0	78.8	81.1	87.5
69.3	78.9	82.0	92.0
71.0	81.4	80.0	90.7
68.8	82.2	80.8	88.4
66.7	79.8	80.9	89.7
72.0	76.7	79.8	88.1
72.8	80.1	80.1	89.4
67.2	78.7	80.4	89.2

Answer 1

At least one mean is different than the other.

Significance level :

We will run the single factor ANOVA here

The p-value is less than the significance level 0.05, hence we can reject the null hypothesis. Thus we have evidence that there is a difference in treatments.