Answer
a) The sample used in the study is all the volunteers who had 8 hours of sleep.
b) The samples population is all the people who took the test.
c) The part of the study that represents the descriptive branch of the statistic is the part that says " three times more likely."
d) If you sleep at least 8 hours you can do better on a math test.
Work Step by Step
a) You can tell this is the sample because it is the fraction of people that the data is based on.
b) You can tell this is the population because this is the whole amount of people the data is based on, not just a fraction of those people.
c) The descriptive branch of the statistics is the part that describes a fact. In this case, "three times more likely" is the fact.
d) This can be inferred with the data presented in the statistic.
