Question

A pharmaceutical firm has requested that a medical doctor observe whether a new version of a drug has actually shortened the length of time it takes for a patient to feel the benefits of the medication. It can be assumed that the reaction times for the drugs are normally distributed. A random sample of 15 subjects received the older version of the drug and had a mean reaction time of 80 minutes with standard deviation of 10 minutes. Another random sample of 10 subjects received the new version of the drug and had a mean reaction time of 65 minutes with standard deviation of 14 minutes. At the 1% level fo significance, test the hypothesis that the new version of the drug shortens the time until the drug benefits are felt.

Answer 1

The test hypothesis is


Now, the value of test static can be found out by following formula:


Using Excel's function =T.DIST(t_0,n-1,TRUE), the P-value for in an power-tailed t-test with 23 degrees of freedom can be computed as
Since , we fail to reject the null hypothesis