22. Which statistical test is used to identify whether there is a relationship between two categorical variables? a) Mann-Whitney test b) Pearson's Chi-square test c) Spearman's correlation test d) Student's t-test 23. A publishing company claims that the average length of its books is more than 1000 pages. In a study, 20 books are randomly selected. The average length within the sample is 1085 pages, and the standard deviation with the sample is 120 pages. Assume that the book lengths in pages are approximately normally distributed. Use a significance level of 0.05 to test the publishing company's claim. a) Ho: Ha b) Test statistic: c) critical value: d) Final conclusion