SOLUTION: 4. Landscaping- Decorative Moon Rocks cost $92 per cu yd. What will be the cost of a conical pile of this rock 3 1/3 yd in diameter and 2 1/4 yd high? Round to nearest dollar.

Algebra ->  Human-and-algebraic-language -> SOLUTION: 4. Landscaping- Decorative Moon Rocks cost $92 per cu yd. What will be the cost of a conical pile of this rock 3 1/3 yd in diameter and 2 1/4 yd high? Round to nearest dollar.      Log On


   

Question 109189: 4. Landscaping- Decorative Moon Rocks cost $92 per cu yd. What will be the cost of a conical pile of this rock 3 1/3 yd in diameter and 2 1/4 yd high? Round to nearest dollar.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Moon Rocks cost $92 per cu yd. What will be the cost of a conical pile of this rock 3 1/3 yd in diameter
and 2 1/4 yd high? Round to nearest dollar.
:
WE know the volume of a cone: V = %281%2F3%29%2Api%2Ar%5E2%2Ah
:
Let the diameter which is given as: 3 1/3 = 10%2F3
Find the radius: 1%2F2 * 10%2F3 = 10%2F6= 5%2F3
and
Let the height which is given as: 2 1/4 = 9%2F4
:
V = %281%2F3%29%2Api%2A%285%2F3%29%5E2%2A%289%2F4%29
:
V = %281%2F3%29%2Api%2A%2825%2F9%29%2A%289%2F4%29
:
Note that in %2825%2F9%29%2A%289%2F4%29 we can cancel the 9:
V = %281%2F3%29%2Api%2A%2825%2F4%29
V = %2825%2F12%29%2Api
V = 6.545 cu yd
:
Cost = 6.545 * 92 = 602.13 = $602