Explain whether each of the following is possible.
a. A relationship exists in the observed sample but not in the population from which the sample was drawn.
b. A relationship does not exist in the observed sample but does exist in the population from which the sample was drawn.
c. A relationship does not exist in the observed sample, but an analysis of the sample shows that there is a statistically significant relationship, so it is inferred that there is a relationship in the population. Exercises 28 to 33 are based on News Story 2, “Research shows women harder hit by hang­overs” and the accompanying Original Source 2. In the study, 472 men and 758 women, all of whom were college students and alcohol drink­ers, were asked about whether they had experienced each of 13 hangover symptoms in the previous year.