This post, on confidence intervals, is by frequent commenter, John Friend. It is the second of our guest posts; the first, by Anthony Harradine, is here. A version of John’s post is also available as a PDF, here. Continue reading “GitS 2 : John Friend – A Lack of Confidence”
Here is one more from the 2019 Specialist Exam 2, once again courtesy of student PURJ (who is vetting the exams much better than the exam vetters). It consists of the last four parts of Q6, the final question on the exam, concerning a machine that packages noodles. The answers from the examination report appear below the questions.
This one is like complaining about the deck chairs on the Titanic, but what the Hell. The WitCH is courtesy of John the Merciless. It is from the 2018 Specialist Mathematics Exam 2:
The Examiners’ Report notes the intended answer:
H0: μ = 150, H1: μ < 150
The Report indicates that 70% of students gave the intended answer, and the Report comments on students’ answers:
The question was answered well. Common errors included: poor notation such as H0 = 150 or similar, and not understanding the nature of a one-tailed test, evidenced by answers such as H1: μ ≠ 150.