20. Using the t-table, give the value of 25th percentile. A. 25 B. 26 C. 27 D. 28 21. What is the t-value of 95th percentile? A. 1.729 B. 1.456 C. 1.612 D. 1.551 22. What degree of freedom should be used to get a t-value of 0.689? A. 1 B. 2 C. 3 D. 4 23. What is the degree of freedom of the data with a sample size of 20? A. 17 B. 18 C. 19 D. 20 24. Find the t-value of 2.5th percentile on the t-table with a degree of freedom of 6. A. 2.570 B. 4.030 C. -2.570 D. -4.030 For number 25-27. Find the length of the following confidence interval. (Use the formula: LCI = UCL - LCL) 25. 0.0254