In a study by Zuckerman and Heneghan (A-3), hemodynamic stresses were measured on subjects undergoing laparoscopic cholecystectomy. An outcome variable of interest was the ventricular end diastolic volume (LVEDV) measured in milliliters. A portion of the data appear in the following table.

Baseline refers to a measurement taken 5 minutes after induction of anesthesia, and the term “5 minutes” refers to a measurement taken 5 minutes after baseline.

LVEDV (ml)

Subject Baseline 5 Minutes 1 51.7 49.3 2 79.0 72.0 3 78.7 87.3 4 80.3 88.3 5 72.0 103.3 6 85.0 94.0 7 69.7 94.7 8 71.3 46.3 9 55.7 71.7 10 56.3 72.3 Source: Data provided courtesy of R. S. Zuckerman, MD.

May we conclude, on the basis of these data, that among subjects undergoing laparoscopic cholecystectomy, the average LVEDV levels change? Let a ¼ :01.