STA2300 Data Analysis - Tutoring 2

Question 4 (20 marks)
Use the information on the Knee girth over patella (cm) and Gender of the California health and fitness clubs from the dataset Body.sav to answer the following questions. You should use SPSS to calculate any sample statistics (eg., mean and standard deviation) you will need to do this question, but for part (e) you are required to do the rest of the calculations by hand, using a calculator.

The fitness specialists wish to check if the mean of the Knee girth over patella (cm) of California health and fitness clubs’ female participants is lower than that of the male participants.

1. (4 marks) Using SPSS produce an appropriate graph to compare the distribution of Knee girth over patella (cm) of the female and male participants of California health and fitness clubs. Label the axes correctly, include unit of measure and provide an appropriate title which includes your name.
2. (2 marks) Using the graph produced in part (a), briefly describe the distribution of Knee girth over patella for the two groups of (male and female) participants. Features discussed should include the shape, centre, spread and outliers, if any.
3. (3 marks) State appropriate hypotheses (defining all symbols) to answer the question: ‘Is the mean Knee girth over patella of female participants is less than that of the male participants?’
4. (2 marks) State (but do not check) the assumptions required for the validity of the test. Describe the assumptions in the context of the study.
5. (2 marks) Without using SPSS, calculate the value of the appropriate test statistic for testing the hypotheses in part (c). [You can use appropriate sample statistics from SPSS output for calculations.]
6. (4 marks) Using the appropriate statistical table provided in the StudyDesk, find the P-value of the test, and describe the outcome of the test in the context of the study.
7. (1 mark) Now use SPSS to check your results for the above hypothesis test. Run the appropriate test procedure in SPSS, and then copy and paste the relevant output for this test into your Tutoring.
8. (2 marks) Briefly comment on how the test statistic and P-value from SPSS output are similar to or differ from your hand calculations.