Step 1.
Set up hypotheses and determine level of significance
Ho:
Ha: Should the alternative hypothesis be upper-tailed, lower-tailed, or two-tailed?
Step 2.
Select the appropriate test statistic
Insert Specific Formula (Consider sample size to determine Z-score or T-distribution)
PROBLEM XVII. A clinical trial is run to assess the effects of different forms of regular exercise on
HDL levels in persons between the ages of 18 and 29. Participants in the study are assigned to one of
three exercise groups-1) weight training, 2) aerobic exercise, or 3) stretching/yoga. They are instructed
to follow their assigned program for 8 weeks. HDL levels are measured in mg/dL after 8 weeks, and are
summarized below. Is there a significant difference in mean HDL levels among the exercise groups?
Run the test at a 5% level of significance. HINT: SSE = 7286.5.
WEIGHT TRAINING
AEROBIC EXERCISE
STRETCHING/YOGA
N
MEAN HDL
STD DEV
(mg/dL)
49.7
10.2
43.1
11.1
20
57.0
12.5
20
20200
Step 3.
Set up decision rule
Do NOT use your level of significance as a part of your decision rule. Be sure to use
only the critical values found in your appendices. Critical values are based upon the type
1. Set Up Hypothesis and Determine Level of Significance
of test used, your sample size or degrees of freedom, your alternative hypothesis
(upper-tailed, lower-tailed, or two-tailed), and your level of significance.
When using a two-tailed test, be sure to include both positive and negative values of the
critical value.
2. Select the Appropriate Test Statistic
Step 4.
Step 5.
Be sure to include the equal sign. For example, "Reject Ho if Z≥ 1.960."
Compute the test statistic.
Please show all computations. If you do not show your computations, you will not
receive credit, even if your test statistic is correct.
Conclusion
There should be two parts to your conclusion-1) Your decision to either reject or fail to
reject the null hypothesis; and 2) You conclusion. Please state both portions. If we reject
the null hypothesis for an upper-tailed test, we can simply say "Reject the null hypothesis
because XXX value is greater than YYY value..."
Your conclusion statement should also reflect the null and alternative hypotheses. For
example, "We have statistically significant evidence to indicate a difference in
3. Set Up the Decision Rule
4. Compute the Test Statistic
5. Decision and Conclusion
