578 / 762
578
Chapter 12: Hypothesis Tests – Large Samples
Now, since the interval ranges from a negative value to a positive value and
so includes the value of zero, one may conclude that there is not a significant
difference between the average times.
That is, both medications seem to have similar effect in reducing the pain
level of the headache and so neither one of them would have an advantage in
reducing the pain level to zero.
Figure 12-35:
Display of the 95% Confidence Interval for the
Difference of the Two Population Means for
Example 12-16
P-Values Revisited
Recall, a general approach in using the
P-
value to help in making a decision
for a test is to compare it with a specified significance level
. The
following was used to help in making a decision about the null hypothesis: