To test for any significant difference in the mean number of hours between breakdowns for four machines, the following data were obtained. Machine 1 Machine 2 Machine 3 Machine 4
6.4 8.7 11.1 9.9
7.8 7.4 10.3 12.8
5.3 9.4 9.7 12.1
7.4 10.1 10.3 10.8
8.4 9.2 9.2 11.3
7.3 9.8 8.8 11.5
The mean times between breakdowns are 7.1, 9.1, 9.9 and 11.4 hours respectively. In the analysis of variance, MSTR = 19.26 and MSE = .97. Use the Bonferroni adjustment to test for a significant difference between all pairs of means. Assume that a maximum overall experiment error rate of .05 is desired.
There are six pairwise comparisons among the 4 machines. What error rate should be used for each pairwise comparison (to 4 decimals)?
Using t = 2.845 for the above error rate, calculate the Bonferroni LSD value (to 2 decimals).
Complete the table below to determine whether there are any significant differences between population means.
Difference Absolute Value Conclusion
1 - 2 SelectSignificant differenceNo significant differenceItem 4
1 - 3 SelectSignificant differenceNo significant differenceItem 6
1 - 4 SelectSignificant differenceNo significant differenceItem 8
2 - 3 SelectSignificant differenceNo significant differenceItem 10
2 - 4 SelectSignificant differenceNo significant differenceItem 12
3 - 4 SelectSignificant differenceNo significant differenceItem 14