Answer:
about $1148.06
Explanation:
Your goal is to find the area of the island of grass and multiply that area by the cost per square yard.
Area = radius * radius * pi
You are told that the diameter = 15 yards. We also know that the radius that we need is half of the diameter. Radius = 7.5 yards.
This means that the Area = 7.5 * 7.5 * 3.14 = 176.625 square yards
Then we multiply by the cost per square yard:
176.625 * 6.50 = 1148.06 is your answer