10. The stimulant Ritalin has been shown to increase atten- tion span and improve academic performance in chil- dren with ADHD (Evans et al., 2001). To demonstrate the effectiveness of the drug, a...

Extracted text: 10. The stimulant Ritalin has been shown to increase atten- tion span and improve academic performance in chil- dren with ADHD (Evans et al., 2001). To demonstrate the effectiveness of the drug, a researcher selects a In sample of n = 20 children diagnosed with the disorder 2 and measures each child’'s attention span before and af- ter taking the drug. The data show an average increase odw of attention span of MD 4.8 minutes with a variance of s = 125 for the sample of difference scores. 9TOW a. Is this result sufficient to conclude that Ritalin bit significantly improves attention span? Use a one- tailed test with a = .05. as %3D %3D %3D are ar 10 dos b. Compute the 80% confidence interval for the mean gnin change in attention span for the population. The