An article in knee surgery, sports traumatology, arthroscopy (2005, vol. 13, pp. 273-279), considered arthroscopic meniscal repair with an absorbable screw. Results showed that for tears greater than 25 millimeters, 14 of 18 (78%) repairs were successful while for shorter tears, 22 of 30 (73%) repairs were successful. (a) Is there evidence that the success rate is greater for longer tears? Use a = 0.05. What is the P-value?
(b) Calculate a one- sided 95% confidence bound on the difference in proportions that can be used to answer the question in part (a).