7. A large IT company has 35,000 employees around the world. The average age of it's emloyees is 35 years old. The company took a random sample of 30 employees in one department and found the average age was 25 years old. a) What is the population size? b) What is the sample size? 8. The BUS 108 course coordinator wants to determine the average student mark for Multiple Choice Quiz 1. There are four BUS 108 classes in Australia with approximately 15 students per class. Once the sample is selected, the coordinator will email the lecturer(s) asking for the MCQ Quiz 1 mark for the selected students. The course coordinator has proposed several types of sampling strategies. Describe the sampling method used for each strategy. a) The coordinator uses the entire BU5108 class list and randomly selects 20 students from this list. b) The coordinator uses the separate class lists of Adelaide, Brisbane, Melbourne and Sydney and randomly selects 5 students from each state's class list. c) The coordinator randomly selects one state's class list. d) The coordinator uses the entire BU5108 class list and selects every 5th student. 9. An internet provider wants to estimate the proportion of its existing customers that would sign up to their new streaming service for movies, tv shows etc. Several sampling strategies have been proposed. For each of these proposed sampling strategies, indicate what type of sampling method is used and what biases, if any, may result. a) Randomly select one street in each city which has many users of this internet provider and door knock households with this provider asking if they would purchase the streaming. b) Go through the internet provider's customer records, selecting every 100th customer and send an email asking if they are interested in purchasing this streaming