7 Turn over 4 Professional tennis players’ prize money is published online. Martina wanted to do an analysis by nationality of top players (those who earned at least $1 million). She randomly selected a year since 2000 and obtained the data for that year to use in her investigation. She then aggregated the results for men and women by region of the world, as shown in Figure 2. Men Women Region of the world Australia and South Africa 4 1 Eastern Europe 11 19 Far East 2 3 South America 3 0 USA and Canada 8 5 Western Europe 29 10 Total 57 38 (Data source: Association of Tennis Professionals and the Women’s Tennis Association) Figure 2 Martina decides to test the hypothesis that, among top players, there is no association between region of the world and sex of player. Martina combines Australia and South Africa, Far East and South America into a single class called Other Regions of the World. (a) Explain why Martina needs to combine regions to carry out her test. You must give numeric justifications. (3) _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________