Sleep debt (3.2) A researcher reported that the typical teenager needs 9.3 hours of sleep per night but gets only 6.3 hours.18 By the end of a 5-day school week, a teenager would accumulate about 15 hours of “sleep debt.” Students in a high school statistics class were skeptical, so they gathered data on the amount of sleep debt (in hours) accumulated over time (in days) by a random sample of 25 high school students. The resulting least-squares regression equation for their data is Sleep debt = 2.23 + 3.17(days).

(a) Interpret the slope of the regression line in context.

(b) Are the students’ results consistent with the researcher’s report? Explain.