1. suppose you wanted to determine whether students who close their eyes are better able to estimate when 30 seconds have passed than students who do not close their eyes.
(you ask students to tell you when to stop a stopwatch after they think 30 seconds have passed.) you find the first 50 students arriving at school one day.
for those 50, you flip a coin to decide whether or not they will close their eyes during the test. then, you compare the amounts by which each group overestimated or underestimated.
a. did this study use random sampling? explain your answer by describing what purpose random sampling serves in such a study.
b. did this study make use of random assignment? explain your answer by describing what purpose random assignment serves in such a study.
c. would the study described above be an observational study or an experimental study? explain how you are deciding.