The article “Application of Surgical Navigation to To-
tal Hip Arthroplasty” (T. Ecker and S. Murphy, Journal
of Engineering in Medicine, 2007:699–712) reports
that in a sample of 113 people undergoing a certain
type of hip replacement surgery on one hip, 65 of them
had surgery on their right hip. Can you conclude that
frequency of this type of surgery differs between right
and left hips?
(a) State the null and alternative hypotheses.
(b) Use a two-sided 95% Agresti confidence interval for thepopulation proportion to conduct this hypoth-
esis test. After constructing your confidence interval, statethe conclusion in the context of the study
and the conclusion of the hypothesis test.
(c) Go ahead and formally conduct the hypothesis test using a =0.05. Calculate the test statistic and
P-value appropriately. Does your conclusion to the hypothesistest agree with part (b)?
