Chapter 10.8, Problem 73E

In Exercise 8.83, we presented some data collected in a study by Susan Beckham and her colleagues. In this study, measurements were made of anterior compartment pressure (in millimeters of mercury) for ten healthy runners and ten healthy cyclists. The data summary is

repeated here for your convenience.

1. a Is there sufficient evidence to justify claiming that a difference exists in mean compartment pressures for runners and cyclists who are resting? Use α = .05. Bound or determine the associated p-value.
2. b Does sufficient evidence exist to permit us to identify a difference in mean compartment pressures for runners and cyclists at 80%maximal O₂ consumption? Use α = .05. Bound or determine the associated p-value.

8.83 Chronic anterior compartment syndrome is a condition characterized by exercise-induced pain in the lower leg. Swelling and impaired nerve and muscle function also accompany the pain, which is relieved by rest. Susan Beckham and her colleagues conducted an experiment involving ten healthy runners and ten healthy cyclists to determine if pressure measurements within the anterior muscle compartment differ between runners and cyclists. The data—compartment pressure, in millimeters of mercury—are summarized in the following table:

1. a Construct a 95% confidence interval for the difference in mean compartment pressures between runners and cyclists under the resting condition.
2. b Construct a 90% confidence interval for the difference in mean compartment pressures between runners and cyclists who exercise at 80% of maximal oxygen (O₂) consumption.
3. c Consider the intervals constructed in parts (a) and (b). How would you interpret the results that you obtained?