Minor surgery on horses under field conditions requires a re

Minor surgery on horses under field conditions requires a reliable short-term anesthetic producing good muscle relaxation, minimal cardiovascular and respiratory changes, and a quick, smooth recovery with minimal aftereffects so that horses can be left unattended. For a sample of n = 73 horses to which ketamine was administered under certain conditions, the sample average lateral recumbency (lying-down) time was 18.86 minutes and the standard deviation was 8.6 minutes. Does this data suggest that true average lateral recumbency time under these conditions is less than 20 minutes? Test the appropriate hypotheses at level of significance .10. What is the appropriate null hypothesis?

Solution

We want to test true average lateral recumbency time under these conditions is less than 20 minutes.

Alternate hypothesis: µ < 20