Question 6 (For Question 6, write down the answers only, no explanation is needed.) (a) State which sampling method (simple random sampling, systematic sampling, stratified random sampling, cluster sampling) is used in each of the following cases: (1) In a private estate with 20 buildings, the property management team wants to conduct a survey to investigate resident's satisfactory level to the service. Two buildings will be selected randomly and all apartments in these two buildings will receive a questionnaire. (2 marks) (ii) Every 1 out of 75 visitors leaving the exhibition center is invited to join a survey about their opinion on the exhibition. (2 marks) (b) State which test (z-test, t-test, ANOVA, X' test) is most suitable for each of the following case ases: (i) In an election, voters may support the Democrat candidate, Republican candidate, or Independent candidate. A researcher would like to conduct a poll to test if this year the supportive rates of the three candidates follow the same supportive rates as in the last election, which was 60% : 25% : 15%. (2 marks) A vaccine is developed for preventing the infection of a disease. An experiment is developed to test its effectiveness. 300 volunteers are divided into two groups randomly. One group of participants will take the vaccine and the other group of participants will not take the vaccine but only vitamin. The proportion of participants in the two groups being infected by the disease will be compared. (2 marks) (iii) A researcher wants to conduct a test to verify if children's outside school learning experiences would be affected by the families' income level. Family income will be classified as high income, middle income, and low income. The average spending on outside school activities per child per month from the three income levels would be compared (2 marks) (Total: 10 marks)