Question

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. An article reports that for a sample of n = 66 horses to which ketamine was administered under certain conditions, the sample average lateral recumbency (lying-down) time was 18.62 min and the standard deviation was 7.7 min. Does this data suggest that true average lateral recumbency time under these conditions is less than 20 min? Test the appropriate hypotheses at level of significance .10. (Round your answers to two decimal places.)

a) What is t?	=
b) What is the P-value?	=

Answer 1

H0: Null Hypothesis: 20

HA: Alternative Hypothesis: < 20

n = 66

= 18.62

s = 7.7

SE = s/

= 7.7/ = 0.9478

Test statistic is:
t = ( - )/SE

= (18.62 - 20)/0.9478 = - 1.4560

ndf = 66 - 1 = 65

One Tail -Left Side test

By Technology, p-value = 0.0751

Since p-value is less than = 0.10, Reject H0.

Conclusion:

The data support the claim that true average lateral recumbency time under these conditions is less than 20 min.

Answers to questions asked:

a) What is t? = - 1.46

b) What is the P-value? = 0.08