The article Sleepless in School describes a study of 282 college students The students were recruited from a general education psychology course a course taken by students from different majors and they were offered extra credit to fill out an online survey The survey included questions about the students sleep health e g hours of sleep during a usual school week as well as questions about possible social determinants of deficient sleep e g food insecurity psychological distress Answer the following four questions for this observational study Hint Reviewing Examples 1 4 and 1 5 might be helpful a What is the population of interest O all students majoring in education psychology all adults O all college students b Was the sample selected in a reasonable way Yes the sample was randomly selected No only college students were represented No the sample size is less than 500 which is too small for a large university No the class had students from a variety of majors but it may not be representative of all majors c Is the sample likely to be representative of the population of interest Yes enough students participated to provide a reasonable estimate of the population O Yes the college student population was well represented O No because only students in this class were selected No the population of interest is all adults and only college students were studied d Are there any obvious sources of bias O Selection bias is present because students who need extra credit may be overrepresented ANOTH O No sampling bias is present O Nonresponse bias is present because not all students enrolled in the course completed the online survey ons were worded poorly