A health psychologist wants to test the effectiveness of a new stress-reduction method. In the general population, stress level is normally distributed with m = 40 and s = 10. A randomly selected person is trained in the method; the person's score afterward is 25.
Population 1:
Population 2:
Research Hypothesis:
Null Hypothesis:
To convert the sample score to Z score use: Z = (X - M) / SD
Sample Score: Z=
Is this a one tailed or two tailed hypothesis?
I want to be sure that my result can only happen 1% of the time if the null hypothesis is true. Use the Z-table to find out what the cutoff should be.
Cutoff Z-Score: Z=
Decision:
Interpretation: