Question

The director of research and development is testing a new drug. She wants to know if there is evidence at the 0.01 level that the drug stays in the system for more than 340 minutes. For a sample of 49 patients, the mean time the drug stayed in the system was 346 minutes. Assume the population standard deviation is 18. State the alternative and null hypotheses.

Answer 1

Solution :

Given that,

= 340

= 346

= 18

n = 49

This will be a right tailed test because the alternative hypothesis is showing a specific direction

This is the right tailed test,

The null and alternative hypothesis is ,

H0 :   = 340

Ha : > 340

Test statistic = z =

= ( - ) / / n

= (346 - 340) / 18 / 49

Test statistic = z = 2.33

P(z > 2.33 ) = 1-P (z < 2.33) = 1 - 0.9901

P-value = 0.0099

= 0.01

P-value <

Reject the null hypothesis