Punxsutawney Phil. In the United States, Groundhog Day is celebrated on February 2. On February 2, Punxsutawney Phil, the legendary groundhog in Punxsutawney, PA, emerges from his home, and if he sees his shadow and returns to his hole, he has predicted six more weeks of winter-like weather. How accurate is Phil? We have data for 116 years (up to 2016) indicating whether Phil saw his shadow and average temperature in March. It is not clear what constitutes six more weeks of winter-like weather, so here we define it to occur if the average temperature for March is not above the historical average. Here we only use temperature data for Pennsylvania, Phils home state. The results are 51 years where Phil saw his shadow and the average March temperature was not above the historical average, 49 years where Phil saw his shadow and the average March temperature was above the historical average, 6 years where Phil did not see his shadow and the average March temperature was not above the historical average, and 10 years where Phil did not see his shadow and the average March temperature was above the historical average.

(a) Make a two-way table of Phil saw his shadow or not against above historical average temperatures in March or not.

(b) What do the data tell us about Phil as a weather forecaster for Pennsylvania?

Q127

Sleep quality. A random sample of 871 students between the ages of 20 and 24 at a large midwestern university completed a survey including questions about their sleep quality, moods, academic performance, physical health, and psychoactive drug use. Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI), with students scoring less than or equal to 5 on the index classified as optimal sleepers, those scoring a 6 or 7 classified as borderline, and those scoring over 7 classified as poor sleepers. The following table looks at the relationship between sleep quality classification and the use of over-the-counter (OTC) or prescription (Rx) stimulant medication more than once a month to help keep awake.

What do the data say about differences in sleep quality for those who use overthe-counter or prescription stimulant medication more than once a month to keep awake and those who dont?