Please use the accompanying Excel data set or accompanying Text file data set when completing the following exercise. An article in the Journal of Aircraft (1986, Vol. 23, pp. 859-864) described a new equivalent plate analysis method formulation that is capable of modeling aircraft structures such as cranked wing boxes and that produces results similar to the more computationally intensive finite element analysis method. Natural vibration frequencies for the cranked wing box structure are calculated using both methods, and results for the first seven natural frequencies follow: Frequency Finite Element, Cycle/s Equivalent Plate, Cycle/s 1 14.58 14.76 2 3 4 5 6 48.52 97.22 113.99 174.73 212.72 277.38 49.10 99.97 117.53 181.22 220.14 294.80 Use only Table V of Appendix A. (a) Do the data suggest that the two methods provide the same mean value for natural vibration frequency? Find interval for P-value: 0.025 < P-value < 0.05 Conclusion: For a significance level of a 0.05, we would reject the null hypothesis. There is evidence to conclude that the two methods provide different mean values for natural vibration frequency. (b) Find a 95% confidence interval on the mean difference between the two methods and use it to answer the question in part (a). Round your answer to 3 decimal places. -10.962 ≤ HD ≤ -0.001 Conclusion: Does the confidence interval indicate that the two methods provide different mean values for natural vibration frequency? sufficient