Final answer:
This study suffers from sampling bias by only observing students who enter a dining hall at a specific time. To avoid bias, the researcher should randomly select students from different locations and times.
Step-by-step explanation:
This study on the eating habits of college students suffers from sampling bias because it only observes students who enter a dining hall between 8:00 A.M. and 8:30 A.M. on a Monday morning. This sample is not representative of the entire population of college students because it excludes those who do not eat breakfast during this specific time period or who do not visit the dining hall at all. This bias can affect the study's results and conclusions because it may not accurately reflect the eating habits of all college students.
To avoid sampling bias, the nutritionist could alter the sampling method by randomly selecting a sample of college students from different locations on different days and times. This would ensure a more diverse and representative sample, allowing for more accurate conclusions about the eating habits of college students.