15. A researcher asks whether people will score higher or lower on a questionnaire measuring their well-being when they are exposed to much sunshine compared to when they’re exposed to little sunshine. A sample of 8 people is measured under both levels of sunshine and produces these well-being scores:

Low: 14 13 17 15 18 17 14 16 High: 18 12 20 19 22 19 19 16

(a) Subtracting low from high, what are Hq and

(b) Compute

(c) With a = .05, what do you conclude about this study?

(d) Compute the appropriate confidence interval,

(e) What is the predicted well-being score for someone when tested under low sunshine? Under high sunshine?

(f) On average, how much more accurate are these predictions than if you did not know how much sunshine people experience? (g) How scientifically important are these results?