A health psychologist noticed that the siblings of his obese patients are often not overweight. He hypothesized

Question:

A health psychologist noticed that the siblings of his obese patients are often not overweight. He hypothesized that the normal-weight siblings consume fewer daily calories than the obese patients. To test this using a matched-pairs design, he compared the daily caloric intake of 20 obese patients to that of a respective normal-weight sibling. The following are the calories consumed for each sibling pair.

Normal-Weight Sibling _________________ Over weight Sibling

1,600 ............................................................2,000

1,800 ............................................................2,400

2,100 ............................................................2,000

1,800 ............................................................3,000

2,400 ............................................................2,400

2,800 ............................................................1,900

1,900 ............................................................2,600

2,300 ............................................................2,450

2,000 ............................................................2,000

2,050 ............................................................1,950

(a) Test whether or not obese patients consumed significantly more calories than their normal-weight siblings at 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 omega-squared.