7. Report and interpret the 95% CI. Let's assume a published op-ed article by a critic of low-cost carriers (LCCs) claims that the aircraft LCCs fly are at least 12 years old and therefore are too old and unsafe. After discussing this article with AMTS who work for various MROS, an aviation researcher believes that the critic is misinformed because LCCs fly newer aircraft that are more fuel efficient and require less maintenance, which helps save costs. To investigate her belief, the researcher randomly selects 20 LCCs from Skytrax (2021), and then consults Airfleets.net (n.d.) to acquire fleet age data for these airlines. The data are provided in the file Ch_4 Review Exercises Part B Data. Assume the population mean is = 12 years, the standard deviation is = 10 years, and the parent population is normally distributed.