This is what I have although it is incorrect any help would be greatly appreciated.!
$\mathbf{1.)}$ Consider now the expression $\frac{a^3+b^3+c^3}{3}$
The expressions has minimum value given by:
$a\geq b \geq c > 0 \implies a^3 \geq b^3 \geq c^3$
Thus $\frac{a^3+b^3+c^3}{3}$ has minimum value $c^3$
$\mathbf{2.)}$ On the other hand, consider the expression $\frac{a^2+bc}{b+c}$
Again we have $a \geq b \geq c >0 \implies a^2+bc \geq c^2+c\cdot c = 2c^2$
$ a \geq b \geq c > 0 \implies a^2+bc \leq a^2 + a \cdot a = 2a^2$
$ a \geq b \geq c > 0 \implies b+c \geq 2c $
and $ a \geq b \geq c > 0 \implies b+c \leq 2a$
$\mathbf{3.)}$ Finally we know that a positive fraction is maximized when the numerator is as large as possible and the denominator is as small as possible
Therefore we have $ \frac{a^2+bc}{b+c} \leq \frac{2a^2}{2c} = \frac{a^2}{c} \leq a $
Using identical considerations, we have $\frac{b^2+ca}{ca} \leq \frac{a^2}{c} \leq a $ and $\frac{c^2+ab}{a+b}\leq \frac{a^2}{c} \leq a$
So that we have
Hence, $\frac{a^2+bc}{b+c} \cdot \frac{b^2+ca}{c+a} \cdot \frac{c^2+ab}{a+b} \leq a^3$
This is the maximum value of the expression
$\mathbf{4.)}$ The minimum value will be achieved for a fraction when the numerator is as small as possible and denominator is as large as possible
Again, by an overall similar consideration, we have $\frac{a^2+bc}{b+c} \geq \frac{a^2+c^2}{2b}$ is the minimum value of this expression
Similarly $\frac{b^2+ca}{c+a} \geq \frac{b^2+c^2}{2a}$ and $\frac{c^2+ab}{a+b} \geq \frac{c^2+b^2}{2a}$
Hence
But we have $a^2+b^2 \geq 2b^2$, $c^2+b^2 \geq 2c^2$
Hence,
Therefore, $\frac{a^2+bc}{b+c} \cdot \frac{b^2+ca}{c+a} \cdot \frac{c^2+ab}{a+b} \geq \frac{bc^4}{a^2}$
$\mathbf{5.)}$ And finally, we have $a^3 \geq abc$ is the maximum value of $abc$
The minimum value of $\frac{a^3+b^3+c^3}{3}$ is $c^3$ which is greater than $a^3$ which is the maximum value of $\frac{a^2+bc}{b+c}\cdot \frac{b^2+ca}{c+a} \cdot \frac{c^2+ab}{a+b}$
That is,
So that $\frac{a^3+b^3+c^3}{3} \geq \frac{a^2+bc}{b+c}\cdot \frac{b^2+ca}{c+a} \cdot \frac{c^2+ab}{a+b} $
Again we have $\frac{a^2+bc}{b+c}\cdot \frac{b^2+ca}{c+a} \cdot \frac{c^2+ab}{a+b} \geq \frac{bc^4}{a^2}$