Question 3. [ 13 marks ] [First half of Chapter 8] Does wearing a wetsuit affect swimming speed? A study investigated this question. 12 competitive swimmers swam 1500 metres as fast as they could on different days, once wearing a wetsuit and once wearing a regular swimsuit (i.e., not wearing a wetsuit). Each swim took place one swimmer at a time, in a 50 metre swimming pool and the order of the swims was randomly allocated. For each swim the maximum speed in metres per second was recorded. Notes: (i) SPSS and Excel files of the data are available on Canvas on the Home Page or look under Assignments Assignment 3. Click on: SwimINZIGHT1 and SwimSPSS1 OR SwimINZIGHT2 and SwimSPSS2 (ii) To answer parts (b), (c) and (d) you need to ensure that you use the files which have the data in the form that is appropriate for the design of this study. (a) For this study describe the: [1 mark] (i) units, (ii) treatment or factor of interest, (iii) response (b) () Use inZight to draw the appropriate plot(s) for this data set. (You should consider the design of this study to ensure the relevant plot(s) is drawn.) [1 mark] (ii) Comment on any features in the plot(s). [3 marks (c) Investigate whether the underlying mean maximum swimming speed when wearing a wetsuit is different to that when wearing a regular swimsuit. Use SPSS to conduct a t-test. Interpret your results. (You should consider the design of this study to ensure the appropriate t-test is conducted.) [6 marks] Notes: (1) You must clearly show that you have followed steps 1, 2, 3, 7, 9 and 10 in the "Step-by-step Guide to Performing a Hypothesis Test by Hand", Lecture Workbook, page 12, Chapter 7. The other steps are replaced by your computer output, which you must hand in (ii) Refer to the instructions on Page 1 of this assignment: "Hypothesis tests in this assignment". (iii) Refer to the appropriate t-test in the SPSS Tutorial, Pages 14 to 16, on Canvas. (Look under Software Information and Help SPSS Help.) (d) Comment on the validity of the t-procedures conducted in (c) by briefly discussing each assumption in terms of the original story. [2 marks] Wetsui t Regula r var 1 1.57 1.49 1.47 1.37 N 3 1.42 1.35 4 1.35 1.27 5 1.22 1.12 6 1.75 1.64 7 1.64 1.59 8 1.57 1.52 9 1.56 1.50 10 1.53 1.45 11 1.49 1.44 12 1.51 1.41 13 14 15 Question 3. [ 13 marks ] [First half of Chapter 8] Does wearing a wetsuit affect swimming speed? A study investigated this question. 12 competitive swimmers swam 1500 metres as fast as they could on different days, once wearing a wetsuit and once wearing a regular swimsuit (i.e., not wearing a wetsuit). Each swim took place one swimmer at a time, in a 50 metre swimming pool and the order of the swims was randomly allocated. For each swim the maximum speed in metres per second was recorded. Notes: (i) SPSS and Excel files of the data are available on Canvas on the Home Page or look under Assignments Assignment 3. Click on: SwimINZIGHT1 and SwimSPSS1 OR SwimINZIGHT2 and SwimSPSS2 (ii) To answer parts (b), (c) and (d) you need to ensure that you use the files which have the data in the form that is appropriate for the design of this study. (a) For this study describe the: [1 mark] (i) units, (ii) treatment or factor of interest, (iii) response (b) () Use inZight to draw the appropriate plot(s) for this data set. (You should consider the design of this study to ensure the relevant plot(s) is drawn.) [1 mark] (ii) Comment on any features in the plot(s). [3 marks (c) Investigate whether the underlying mean maximum swimming speed when wearing a wetsuit is different to that when wearing a regular swimsuit. Use SPSS to conduct a t-test. Interpret your results. (You should consider the design of this study to ensure the appropriate t-test is conducted.) [6 marks] Notes: (1) You must clearly show that you have followed steps 1, 2, 3, 7, 9 and 10 in the "Step-by-step Guide to Performing a Hypothesis Test by Hand", Lecture Workbook, page 12, Chapter 7. The other steps are replaced by your computer output, which you must hand in (ii) Refer to the instructions on Page 1 of this assignment: "Hypothesis tests in this assignment". (iii) Refer to the appropriate t-test in the SPSS Tutorial, Pages 14 to 16, on Canvas. (Look under Software Information and Help SPSS Help.) (d) Comment on the validity of the t-procedures conducted in (c) by briefly discussing each assumption in terms of the original story. [2 marks] Wetsui t Regula r var 1 1.57 1.49 1.47 1.37 N 3 1.42 1.35 4 1.35 1.27 5 1.22 1.12 6 1.75 1.64 7 1.64 1.59 8 1.57 1.52 9 1.56 1.50 10 1.53 1.45 11 1.49 1.44 12 1.51 1.41 13 14 15