A study reported in the Journal o,f Psychology (Mar.

1991) measures the change in female students' selfconcepts as they move from high school to co1lege.A sample of 133 Boston College first-year female students wasselected for the study. Each was asked to evaluate several aspects of her life at two points in time: at the end of her senior year of high school, and during her sophomore year of college. Each student was asked to ev&uate where she believed she stood on a scale that ranged from top 10% of class (1) to lowest 10% of class

(5). The results for three of the traits evaluated are reported in the second table on p. 373.

a. What null and alternative hypotheses would you test to determine whether the mean self-concept of females decreases between the senior year of high school and the sophomore year of college as measured by each of these thrce traits?

b. Are these traits more appropriately analyzed using an independent samples test or a paired difference test? Explain.