Question

A health psychologist tests a new intervention to determine if it can change healthy behaviors among siblings. To conduct this test using a matched-pairs design, the researcher gives one sibling an intervention, and the other sibling is given a control task without the intervention. The number of healthy behaviors observed in the siblings during a 5-minute observation was then recorded.

Intervention
Yes	No
6	4
2	5
5	4
6	5
6	4
5	4

(a) Test whether or not the number of healthy behaviors differs at a 0.05 level of significance. State the value of the test statistic. (Round your answer to three decimal places.)

State the decision to retain or reject the null hypothesis.

(b) Compute effect size using eta-squared. (Round your answer to two decimal places.)