(9 WWW, awua l ekstom Q DESCPlPTIVE STATISTICS Identifying and reducing statistical bias l Abdulrahman V v (Espanoi ; A local high school has 2200 students. The principal wants to study the prevalence of using the internet to cheat on schoolwork among students at the school. She takes a random sampl_e of 16 students and calls them to her office one at a time. There, she asks them this question. Do you use online resources to cheat on your schoolwork? Of the sampled students, 6.25% said that they use online resources to cheat, and the rest said that they don't. (a) Identify and describe the most prominent source of bias in the principal's study. Choose the best answer from the choices below. O The bias comes from the phrasing of the question and the context in which it is asked. Students at the school are unlikely to respond to the principal's question truthfully. O The bias comes from having too many of the sampled students not respond to the question. These students might answer the question differently than those who did. 0 The bias comes from the fact that the students were not allowed to voluntarily choose to be In the sample. Volunteers are more likely to have characteristiz: that reflect the population as a whole. 0 The bias comes from the sampling done in the study. The principal only sampled from students at the school, so the sample is a sample of convenience. 0 There is no or very little bias in the principal's study. The sample size is smaller than 30. Samples of this size are very unlikely to have outliers, meaning that the sample will have characteristics that reect the population as a whole. (b) Describe something the principal could have done to reduce the most prominent source of bias in the study. Choose the best answer from the choices below. 0 Modify the study to also Include members of the school's alumni list in the sample. This way the sample is no longer a sample of convenienoe. 0 Make sure that the students could answer the question anonymously, and consider changing the phrasing of the question so that students would be more likely to answer truthfully. 0 Offer a small reward to the students in the sample for answering the question. This way the number of students not responding would be decreased. 0 Email the entire student body and let them know there Will be a special aereschool discussion on cheating that students are invited to attend if they wish. This way the principal makes sure the respondents are volunteers. 0 As the sample size is sufciently small, the study has no or very little bias. So, there is nothing the principal needed to have done to reduce bias