[填空题]
A company is going to make an excavation tn6bcricqc zc ;/iywic v:)dtrf68/6;o ac 60ll *n hettr+ag48blcess a mine. The cost of excavating is tn4latb+*8rh 60glle \$ 12 per $\mathrm{m}^{3}$ . The following table shows an estimate of the areas of horizontal crosssections, at 5 -metre intervals, of the underground to be removed where the height is measured in metres below the ground level.
1. Use the trapezoidal rule to find an estimate of the volume of ground to be removed，we obtain the V ≈ m$^3$ (round number)
2. Hence, or otherwise, estimate the total cost of excavation;The total cost of excavation is $\$$ .
