In the article “Lower Lateral Cartilage Repositioning Objective Analysis Using 3-

Dimensional Imaging” published in JAMA Facial Plastic Surgery (Bared, et al., 2014), the authors reported the results of a paired comparison study of pre- and postoperative angle change for lower lateral cartilage repositioning. Based on ???? = 32 angle change measurements (post-pre), ????̄ = 13.00 and ???????? = 8.73 and the authors reported that the differences appeared to be normally distributed.

(a) Determine the rejection region for test ????0 ∶ ???????????????????? ≤ ???????????????? for ???? = 0.01.

(b) Compute the value of ????obs.

(c) Based on parts

(a) and

(b) is there sufficient statistical evidence to conclude

???????????????????? > ????????????????? Why?

(d) Compute a 95% confidence interval for ???????????????????? − ????????????????.