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 331 minutes. For a sample of 87 patients, the mean time the drug stayed in the system was 335 minutes. Assume the standard deviation is known to be 23.

Step 1 of 5:

Enter the hypotheses:

Step 2 of 5:

Enter the value of the z test statistic. Round your answer to two decimal places.

Step 3 of 5:

Specify if the test is one-tailed or two-tailed.

Step 4 of 5:

Enter the decision rule.

Step 5 of 5:

Enter the conclusion.

Answer 1

Solution :

= 331

=335

=23

n = 87

a )This is the right tailed test .

The null and alternative hypothesis is ,

H0 :    = 331

Ha : > 331

b ) Test statistic = z

= ( - ) / / n

= (335-331) / 23 / 87

= 1.62

Test statistic = z =1.62

c )P(z >1.62 ) = 1 - P(z < 1.62 ) = 1 -0.9474  

P-value =0.0526

= 0.02  

P-value >

0.0526 > 0.02

d )Fail to reject the null hypothesis .

e ) There is insufficient evidence to suggest that