Question

Neutering dogs is a common surgical practice. The mean time to recover from the general anesthetic used is 26 hours. A veterinarian believes that since changing to a new anesthetic, the mean recovery time is shorter than before. From a random sample of 40 surgeries with the new anesthetic, she finds the mean recovery time was 25 hours with a standard deviation of 2.5 hours. What is the p-value for her hypothesis test

Answer 1

0.005719

Explanation:

H0 : μ = 26

H1 : μ < 26

Given that:

Population mean, μ = 26

Sample mean, xbar = 25

Sample standard deviation, s = 2.5

Sample size, n = 40

The test statistic :

(xbar - μ) / s/sqrt(n)

Test statistic :

(25 - 26) / 2.5/sqrt(40)

-1 / 0.3952847

Test statistic = - 2.5298

Using a Pvalue calculator from Z test statistic:

Pvalue = 0.005719