A study of the properties of metal plate-connected trusses usedfor roof support yielded the following observations on axialstiffness index (kips/in.) for plate lengths 4, 6, 8, 10, and 12in:
4: | 319.2 | 409.5 | 311.0 | 326.5 | 316.8 | 349.8 | 309.7 |
6: | 441.1 | 347.2 | 361.0 | 404.5 | 331.0 | 348.9 | 381.7 |
8: | 390.4 | 366.2 | 351.0 | 357.1 | 409.9 | 367.3 | 382.0 |
10: | 364.7 | 452.9 | 461.4 | 433.1 | 410.6 | 384.2 | 362.6 |
12: | 408.4 | 441.8 | 419.9 | 410.7 | 473.4 | 441.2 | 465.8 |
Does variation in plate length have any effect on true averageaxial stiffness? State the relevant hypotheses using analysis ofvariance.
H0: μ1 ≠μ2 ≠μ3 ≠μ4 ≠μ5
Ha: at least twoμi's are equalH0:μ1 ≠μ2 ≠μ3 ≠μ4 ≠μ5
Ha: all five μi'sare equal    H0:μ1 = μ2 =μ3 = μ4 =μ5
Ha: all five μi'sare unequalH0: μ1 =μ2 = μ3 =μ4 = μ5
Ha: at least twoμi's are unequal
Test the relevant hypotheses using analysis of variance withα = 0.01. Display your results in an ANOVA table. (Roundyour answers to two decimal places.)
Source | Degreesof freedom | Sum of Squares | Mean Squares | f |
---|
Treatments | | | | |
Error | | | | |
Total | | | | |
Give the test statistic. (Round your answer to two decimalplaces.)
f =
What can be said about the P-value for the test?
P-value > 0.1000.050 < P-value <0.100Â Â Â Â 0.010 < P-value <0.0500.001 < P-value < 0.010P-value <0.001
State the conclusion in the problem context.
Fail to reject H0. There are no differencesin the true average axial stiffness for the different platelengths.Reject H0. There are differences in thetrue average axial stiffness for the different platelengths.    Reject H0.There are no differences in the true average axial stiffness forthe different plate lengths.Fail to reject H0.There are differences in the true average axial stiffness for thedifferent plate lengths.