Simulation 8 (A): Unit Rating In 2017 simulation activities have been introduced in BSB123 tutorials. The unit coordinator surveys a random sample of 20 students to determine if the average unit satisfaction rating in 2017 has improved at 5%. The average unit satisfaction rating in 2016 was 7. Learning Objective : To investigate the various factors that will influence our decision to reject (or not to reject) the null hypothesis These factors include: how far the sample mean ( X ) is from the hypothesised value, variability of sample observations (s), and sample size (n). In this simulation, you will be asked to create several scenarios to investigate how the sample size, sample mean and sample standard deviation will influence your decision Scenario 1 You are given a sample with a mean rating of 7.4. Follow the instructions in the worksheet to conduct a test with the given sample date. You should come to the conclusion of not rejecting the null hypothesis. This is the baseline scenario Scenario 2 You alter some observations to increase the sample mean rating to 7.6 such that you can reject the null hypothesis. Scenario 3 You alter some observations to increase the sample mean rating to 7.6, but you still cannot reject the null hypothesis. Scenario 4 You alter some observations without increasing the sample mean rating (i.e. X = 7.4) but you can reject the null hypothesis. Scenario 5 You add 30 more observations to increase the sample size to 50, with the same sample mean ( X ) and sample standard deviation (s) as the baseline scenario Discussion : In Scenario 3, you cannot reject the null hypothesis by increasing the sample mean to 7.6 whereas in Scenario 2 you can. Why? In Scenario 4, why can you reject the null hypothesis even though the sample mean is unchanged ? In Scenario 5, both the sample mean and sample standard deviation are the same as Scenario 1. Why can you reject the null hypothesis in Scenario 5 but not Scenario 1