Within each leaf node (i.e., the nodes at the bottom of the figure), what does the top number in each leaf node represent? More specifically, what do the values 19, 20, 22, 24, etc represent in the following figure?

A regression tree where the median college ACT score was the outcome and various aspects of the institutions were used as predictor attributes. Below the important attributes when predicting the median college ACT score are shown where tuition fees for out of state (tuitionfee_out), tuition fees for in state (tuitionfee_in), undergraduate enrollment (ugds), admission rate (adm_rate), median graduate student debt (grad_debt_mdn), and median student debt (debt_mdn) were identified as important predictors.

Options:

The number of colleges (i.e., the amount of data) found in each leaf node.

The predicted median college ACT score in that leaf node.

The likelihood of each college being assigned to each leaf node.