Hypothesis Testing and Significance- Worksheet
1. Assume we have conducted an experiment to test the hypothesis that Medicine A affects
the appetites of advanced-stage renal failure patients. For this study, we have sampled 20
advanced-stage renal failure patients.
a. What is the nondirectional alternative hypothesis?
b. What is the null hypothesis?
c. If P < 0.05, using α= 0.052 tail what do you conclude?
d. What error may you be making by your conclusion in part c?
e. To what population does your conclusion apply?
2. You have good reason to believe that a particular gaming app is causing increased violence
in adolescents. To test this hypothesis, you conduct an experiment in which 14 individuals
are randomly sampled from adolescent students attending high school X. Each subject is
run in an experimental and a control condition. In the experimental condition, the
adolescents play the game for 2 months during which you record the number of violent acts
committed. The control condition also lasts for 2 months, but the adolescents are not
allowed to play the game during this period.
a. What is the directional alternative hypothesis?
b. What is the null hypothesis?
c. If P = 0.174, using α= 0.011 tail what do you conclude?
d. What error may you be making by your conclusion in part c?
e. To what population does your conclusion apply?
3. A workplace psychologist believes that yoga affects overall workplace productivity. To
investigate this possibility, 12 employees of the corporation are randomly selected to
participate in a yoga program. Before beginning the program, they are given a
questionnaire to measure their productivity at work. Then they begin the yoga program.
The program consists of a beginner’s yoga flow for 30 minutes a day, 4 days a week. Each
employee’s productivity is measured again after 3 months on the program.
a. What is the alternative hypothesis? Use a non-directional hypothesis.
b. What is the null hypothesis?
c. If P = 0.02, using α= 0.051 tail what do you conclude?
d. What error may you be making by your conclusion in part c?
e. To what population does your conclusion apply?
Adapted from: Pagano, R. R. (2001). Understanding statistics in the behavioral sciences. Pacific Give, CA: Brooks/Cole Publishing Company.