Discussion:
Q An experiment was carried out on scale models in a wave tank to investigate how the choice of mooring method affected the bending stress produced in a device used to generate electricity from wave power at sea. The model system was subjected to the same sample of 18 sea states with each of the two mooring methods. The resulting data (root mean square bending moment in Newton meters) are
Sea state Method 1 Method 2
1 2.23 1.82
2 2.55 2.42
3 7.99 8.26
4 4.09 3.46
5 9.62 9.77
6 1.59 1.4
7 8.98 8.88
8 0.82 0.87
9 10.83 11.2
10 1.54 1.33
11 10.75 10.32
12 5.79 5.87
13 5.91 6.44
14 5.79 5.87
15 5.5 5.3
16 9.96 9.82
17 1.92 1.69
18 7.38 7.41
a. Conduct the appropriate hypothesis test using a 0.10 significance level.
b. Construct a 90% confidence interval for the true mean difference in bending stress.
c. What did you assume to do the analysis? Can you evaluate how well these data meet the assumptions? If yes, determine how comfortable you are with them. If not, explain why.