Answer
S=0.7683
s=0.5183
Work Step by Step
Let S be the upper sum and s be the lower sum.
There are four intervals between 0 to 1 so the intervals are $(0,\frac{1}{4}),(\frac{1}{4},\frac{2}{4}) ,(\frac{2}{4},\frac{3}{4}), (\frac{3}{4},\frac{4}{4})$.
Therefore
$S=\frac{1}{4}\Sigma _{x=1}^{4} f(x)= \frac{1}{4} \sqrt \frac{1}{4} + \frac{1}{4} \sqrt \frac{2}{4} + \frac{1}{4} \sqrt \frac{3}{4}+ \frac{1}{4} \sqrt \frac{4}{4} = 0.7683$
$s=\frac{1}{4}\Sigma _{x=0}^{3} f(x)= \frac{1}{4}\sqrt0+\frac{1}{4} \sqrt \frac{1}{4} + \frac{1}{4} \sqrt \frac{2}{4} + \frac{1}{4} \sqrt \frac{3}{4}= 0.5183$
