A Washington Post article "Is college too easy? As study time falls, debate rises" (May 21, 2012) stated that the amount of time college students actually study has dwindled from an average of 24 hours per weektoabout15hours(basedonasurvey).Aprofessorofstatisticsdecidedtoaskallofhiscurrent semester students to report the number of hours per week they spend studying his course material (on a regular, non-exam week).The mean for the female students was 10 hours and the standard deviation was 3.5 hours.

A. Consider the following interpretations of the standard deviation and select those that are correct.

• On average, the number of hours spent studying statistics varied from the mean by about 3.5 hours.
• The average distance between the number of hours spent studying statistics is roughly 3.5 hours.
• The average number of hours spent studying statistics is about 3.5 hours away from the mean.

B. Juan learns that he is in the top 30% of the studying distribution.Based on the distribution, Juan must study at least how many hours per week?Make a hand sketch of what you are trying to find to help show your work.