Question

The director of research and development is testing a new drug. She wants to know if there is evidence at the 0.05 level that the drug stays in the system for more than 399minutes. For a sample of 81patients, the mean time the drug stayed in the system was 401 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

Solution :

This is the right tailed test .

The null and alternative hypothesis is ,

H0 :   =399

Ha : > 399

Test statistic = z

= ( - ) / / n

= (401-399) / 21/ 81

Test statistic = 0.8572 rounded 0.86

P(z > 0.86) = 1 - P(z < 0.86) = 1-0.8051=0.1949

P-value = 0.1949

=0.05

P-value >

Reject H0 :