Question

The director of research and development is testing a new drug. She wants to know if there is evidence at the 0.02 level that the drug stays in the system for more than 385 minutes. For a sample of 42 patients, the mean time the drug stayed in the system was 389 minutes. Assume the population standard deviation is 21. Find the P-value of the test statistic. Round your answer to four decimal places.

Answer 1

This is the right tailed test .

The null and alternative hypothesis is

H₀ :   = 385

H_a : > 385

Test statistic = z

= ( - ) / / n

= (389 - 385) / 21 / 42

Test statistic = 1.23

P(z > 1.23) = 1 - P(z < 1.23) = 0.1093

P-value = 0.1093