1 (4.3) Study of adolescents with ADHD. Children with attention-deficit/hyperact
ID: 3051591 • Letter: 1
Question
1 (4.3) Study of adolescents with ADHD. Children with attention-deficit/hyperactivity disorder (ADHD) were monitored to evaluate their risk for substance (e.g., alcohol, tobacco, illegal drug) use Journal of Abnormal Psychology, August 2003). The following data was collected on 142 adolescents diagnosed with ADHD: y frequency of marijuana use the past 6 months x1 = severity of inattention (5-point scale) X2 = severity of impulsivity-hyperactivity (5-point scale) x,-level of oppositional-defiant and conduct disorder (5-point scale) (a) Write the equation of a first-order model for E(v). (b) The coefficient of determination for the model is R2 = 0.08. Interpret this value. (c) The global F-test for the model yielded a p-value less than 01. Interpret this result. (d) The t-test for Ho: 0 resulted in a p-value less than .01. Interpret this result. (e) The t-test for Ho: -0 resulted in a p-value greater than .05. Interpret this result. (f) The t-test for Ho: = 0 resulted in a p-value greater than .05. Interpret this result.Explanation / Answer
a)) The equation of first order model for E(y) is given by:
E(y) = b0 + b1*x1+ b2*x2+ b3*x3
b)) the coefficient of determination is given as:
R2 = 0.08. Which shows that around 8 percent of variation in marijuana use accounted for by the independent variables in the model (x1, x2 and x3).
c)) F-test used to whether R2 is different from zero. Here, we have provided the p-value is less than .01, thus we are going to reject the null hypothesis. Thus, R2 is different from zero.
d)) Two-tailed p-values test the hypothesis that each coefficient is different from zero. Here, in the question, we have provided that p-value is less than 0.01, thus we reject the null hypothesis, we have found that coefficient of x1 is not equal to zero.
e)) Here, in the question, we have provided that p-value is less than 0.01, thus we reject the null hypothesis, we have found that coefficient of x2 is not equal to zero.
f)) Here, in the question, we have provided that p-value is less than 0.01, thus we reject the null hypothesis, we have found that coefficient of x3 is not equal to zero.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.