In: Statistics and Probability
The guidelines for the Jolly Blue Giant health insurance company say that the average hospitalization for a triple hernia operation should not exceed 30 hours. A diligent auditor studied the records of 16 triple-hernia operations randomly selected at Hackmore Hospital and found an average hospital stay of 40 hours with a standard deviation of 20 hours. "Aha!" He exclaimed, "the average stay exceeds the standard." The p-value for this hypothesis test is
Select one: a. between .05 and .10
b. between .025 and .05
c. between .01 and .025
d. less than .01
Ho : mu = 30
H1 : mu>30
we use t test since the sample is less than 30
t = xbar - mu / (s/√n)
40 -30 / (20/√16) =2
P value at t = 2 at d.f 15 is 0.031 so the appropriate p vaoue interval for rejection of null hypothesis is 0.05 to 0.10.