Pls show all workings Thx Five business people who fiy frequ

Pls show all workings. Thx.

Five business people who fiy frequently were asked to evaluate four airlines that they have used before based on 20 questions on 5-point Likert scale. The results are shown below: Test at the 5% level of significance if the variance of scores for airline D is less than 150. Provide a 95% lower-sided confidence interval for the true variance. Test at the 5% level of significance if the variances of scores for airlines B and D differ. Provide a 95% 2-sided confidence interval for the ratio of true variances. Test at the 5% level of significance if the mean scores differ across airlines using the Friedman test.

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