Question

At Rachel's 11hirthday party, & girls were timed to see how long (in seconds) they could hold their breath in a relaxed position. After a two-minute rest, they timed themselves while jumping. The girls thought that the mean difference between their jumping and relaxed times would be zero. Test their hypothesis at the 5% level. Relaxed time (seconds) 25 46 Jumping time (seconds) 20 41 26 30 22 21 23 25 45 43 37 .75 29 32 NOTE: If you are using a Student's t-distribution for the problem, including for paired data, you may assume that the underlying population is normally distributed. (In general, you must first prove that assumption, though.) Part(a) Part(b) Part (0) Part(d) Part(ci What is the test statistic? (If uelng the z distibution round your answer to two decimal places, and it using the t distribution round your answer to three decimal places.) X

Answer 1

y 20 d=x-y 5 5 d? 25 25 25 4 16 1 1 -2 4 46 41 30 26 22 21 23 25 45 43 37 35 29 32 Total 4 2 2 -3 4 9 88 14 Here n= 8 Σd d= 1.8 n 1 (d)) S = 3.011881 n- 1d n t= d 8d = 1.643 (A)