8.6 Use the ADD data set and fit a logistic regression model to predict whether a student dropped out before completing high school from average ADD score (ADDSC) only.

a. Fully interpret the value, direction, and statistical significance of the slope estimate in this model.

b. Does this model provide significantly better fit (or prediction) than a model with no predictors? Report the appropriate test statistic, df, and p-value to support your answer.

c. Conceptually, or in terms of the null hypothesis tested, how does the test in part (a)

compare to the test in part (b)?