1.When an independent sample is selected, are the same or different participants observed in each group?

2. In the following studies, state whether you would use a one-sample t test or a two-independent-sample t test.

a. A study testing whether night-shift workers sleep the recommended 8 hours per day

b. A study measuring differences in attitudes about morality among men and women

c. An experiment measuring differences in brain activity among rats placed on either a continuous or an intermittent reward schedule

3. State the degrees of freedom for the t test for each of the following

situations in which two groups are observed.

a.A study in which 12 participants are assigned to one group and 15 participants are assigned to a second group

b. A study in which 30 participants are selected, then half are observed in Group 1, and half in Group 2

c.A study in which researchers compare the standardized test scores between a class of 20 psychology students and a class of 26 biology students

4. State the critical values for a two-independent-sample t test given

the following conditions:

a.Two-tailed test, = .01, total df =26

b.One-tailed test, lower-tail critical, = .01, df = 15 for each group

c.Two-tailed test, = .05, n = 12 in each group

d.One-tailed test, upper-tail critical, = .05, n for both groups combined is 30

5. A study evaluating the effects of parenting style (authoritative, permissive) on child well-being observed 20 children (10 from parents who use an authoritative parenting style and 10 from parents who use a permissive parenting

style). Children between the ages of 12 and 14 completed a standard child health questionnaire where scores can range between 0 and 100, with higher scores indicating greater well-being. The scores are given in the table.

(Authoritative: M=65.00; Variance=83.36) (Permissive: M=73.50; Variance=111.30)

Authoritative parenting: 60, 65, 70, 65, 80, 50, 75, 55, 60, 70

Permissive parenting: 80, 75, 55, 85, 90, 65, 70, 65, 70, 80

a.Test whether or not child health scores differ between groups using a .05 level of significance. State the value of the test statistic and the decision to retain or reject the null hypothesis

b.Compute effect size using estimated Cohen's d

6. Individual actions can play a large role in the overall health of our planet. A researcher interested in evaluating environmentally friendly behaviors evaluated how often people recycle (per month) based on whether they have an overall optimistic or an overall pessimistic attitude toward eco-friendly behaviors. The results from this hypothetical study are given in the table.

(Authoritative: M=65.00; Variance=83.36) (Permissive: M=73.50; Variance=111.30)

Pessimistic: 3, 0, 4, 2, 1,6, 3, 5, 0, 5

Optimistic: 4, 9, 6, 8, 9, 5, 6, 8, 6, 7

a. Test whether or not recycling behaviors differed between groups using a .05 level of significance. State the value of the test statistic and the decision to retain or reject the null hypothesis.

b.Compute effect size using eta-squared (²).