A researcher wants to know if students who eat breakfast perform better in their classes. She randomly chooses 200 students and distributes a survey about their breakfast habits. She collects information about their grades from the record office. She finds that students who regularly ate breakfast had a GPA 0.6 points higher than those who ate breakfast fewer than 4 days a week.

is the scenario observational or experiment. If it's experiment identify the control and treatment group and state whether blinding is needed?

if study is observational state whether it is a case control study, if so identify the cases and controls

If the