Problem 54E

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:

(a) Do the data suggest that the two methods provide the same mean value for natural vibration frequency? Use α = 0.05. Find the P-value.

(b) Find a 95% confidence interval on the mean difference between the two methods.

Chapter 1: Introducing Stats Statistics- “Set of mathematical procedures for organizing, summarizing, and interpreting data.” Basically, just making sense of numbers for large amounts of data Functions Organize Data Graphs and Tables Collect and examine information No calculations or manipulations Visual displays Summarize: Descriptive Stats Represent information Reduce information to single values Simplest manipulations and calculations Overall Idea of the data Interpret Compare summarized in