Riemann Sum: Solve for Area Under Curve 0 to 18

[blahblah33]

Riemann sum help!

Homework Statement

Use Riemann sum with c_i= i³/n³
f(x)= $$\sqrt[3]{x}$$ +12
from x=0 to x=18
n= 6 subintervals
Approximate the sum using Riemann's Sum

Homework Equations

$$\Sigma f(ci) \Delta$$ xi
is the equation for riemanns sum i think

The Attempt at a Solution

i tried plugging in stuff using that, but i must've done something wrong because the answer i got was 200 off the actual area under the curve...

 

[blahblah33]

also, is my original equation for riemann's sum correct? is there a limit involved?