In a recent study, volunteers who had 8 hours of sleep were three times more likely to

Question:

In a recent study, volunteers who had 8 hours of sleep were three times more likely to answer questions correctly on a math test than were sleep-deprived participants.
(a) Identify the sample used in the study.
(b) What is the sample’s population?
(c) Which part of the study represents the descriptive branch of statistics?
(d) Make an inference based on the results of the study.