Hypothesis Testing

For each of the following three research scenarios:

a) state the null hypothesis

b) specify whether a one- or a two-tailed test was used

1. A study on the gender income gap among older adults where the main researcher believes that the

average income of elderly women is lower than the average income of elderly men.

2. A survey-based study trying to determine if there is a difference in the amount of study time oncampus

and off-campus students devote to their schoolwork during an average week.

3. A study testing that stress (measured on an ordinal scale) is lower for adults who own dogs (or other

pets) than for non-pet owners.

4. What is the difference between a Type I error and a Type II error?

5. If a two-tailed probability is 0.07, what is the one-tailed probability if the effect were in the specified

direction?

6. True or False: it is easier to reject the null hypothesis using an alpha of 0.05 than an alpha of 0.01.

7. True or False: it is easier to reject the null with a two-tailed test than with a one-tailed test using the

same confidence level.