Question: Recent results suggest that children with A DH D tend to watch more TV than children who are not diagnosed with the disorder. To examine this relationship, a researcher obtains a random sample of n=36 children, 8 to 12 years old, who have been diagnosed with ADHD. Each child is asked to keep a journal recording how much time each day is spent watching TV. The average daily time for the sample is M=4.9 hours. It is known that the average time for the general population of 8 to 12 year old children is μ⁼4.1 hours with σ=1.8.

a. Are the data sufficient to conclude that children with ADHD watch significantly more TV than children without the disorder? Use a two-tailed test with α=0.05.

b. If the researcher had used a sample of n=9 children and obtained the same sample mean, would the results be sufficient to reject H0?

c. Compute Cohen’s d for this study. (Notice that the value you obtain does not depend on whether the sample size was n=36 or n=9.)