$(10$ points$)$ Consider the following training data set for a decision tree.

$\backslash$table$[[$Instance$,a{a}_1,\frac{?}{\text{b}\text{a}\text{r}}(a_2),,$Target Class$],[1,\backslash$table$[[$T$]],$T$,2\mathrm{.}0,\backslash$table$[[+],[+],[+],[+],[+],[+],[-]]],[2,T,$T$,6\mathrm{.}0,],[3,T,Fs,5\mathrm{.}0,],[4,F,$F$,4\mathrm{.}0,],[5,F,T?,7\mathrm{.}0,],[6,F,$T $3,3\mathrm{.}0,],[7,$F$,$F $?,7\mathrm{.}0,],[8,T,$T $8,8\mathrm{.}0,],[9,T,$T $2,4\mathrm{.}0,]]$

a$)$ Compute the Gini index for the overall collection of training examples.

b$)$ Compute the Gini index for each of the attributes.