Question Statement:
An excavated dugout farm pond has a top surface area of 400 m$^2$, a bottom area of 100 m$^2$, and a depth of 3.0 m. Using the Prismoidal formula $V = \frac{D}{6}(A_1 + 4 A_m + A_2)$ where $A_m$ is area at mid-depth (length and width are mid-values: top 20m $\times$ 20m, bottom 10m $\times$ 10m $\implies$ mid 15m $\times$ 15m $= 225\text{ m}^2$), the storage volume in m$^3$ is: