The rectangles in the graph below illustrate a left$-$endpoint rectangles for $f(x)=\frac{13}{x}$ on the interval $4,8.$

The value of the left Riemann sum is $,$ and this sum is the area trapped between the graph of $y=f(x)$ and the $x-$axis on the interval $4,8.$

Note: You will need a calculator for this problem.

Left endpoint Riemann sum for $y=(\frac{13}{x})$ on $4,8$