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

Sol

In excel install analysis toolpak and then go to

Data>Data analysis>ANOVA single factor we get

Output:

Ho:All the 4 group means are equal

Ha:Atleast one of the group means are different

alpha=0.05

From ANOVA table:

F=289.8985687

p=0.000

p<0.05

Reject Ho

Accept Ha

Conclusion:

There is sufficient statistical evidence at 5% level of significance to conclude that there is a difference in treatments of the 4 groups.