Answer: D) 487 is the most accurate of the four recorded because it is the nearest number to the perimeter of the whole backyard i.e.488 feet.
All of the options can be written as
A)486 feet and 6 inches=486 feet and 0.5 feet=486.5 feet [1 feet=12 inches ∴ 6 inches=0.5 feet]
B)486.5 feet C)486.55 feet D)487 feet
Arrange them into increasing order we get
A)=B)=486.5 feet <C)486.55 feet<D)487 feet<488 feet←perimeter of backyard.
here D) 487 is the nearest value to the the perimeter of backyard. Therefore 487 is the most accurate of the four recorded.