The rectangles in the graph below illustrate a right endpoint Riemann sum for $f(x)=(\frac{16}{x})$ on the interval $[4.8].$ The value of this right endpoint Riemannn sum it

$8.$

and this Riemann sum

i

the area of the region enclosed by $y=f(x),$ the $x-$axis, and the vertical lines $x=4$ and $x=$