In a chaotic world far far away, a professor notices that hisstudents begin to miss classes randomly- they either show up or notwith no preference. So he decides to take attendance. There are atotal of eight classes in the semester. He knows that if he takesattendance each time, he will have an absolutely accuratemeasurement of his students' overall attendance rate (6/8, 7/8etc). But he gets lazy and wants to take attendance every otherclass (his students don't know about this). Now each attendancecounts for two: if a student shows up in 3 of the 4 times theprofessor takes attendance, he gets an overall attendance rate of6/8. In this case, what is the professor's measurement error of astudent's actual attendance rate? What if the professor takeattendance only twice (each counts for four)? What if he only takesattendance once (counts for eight)?
