A cubic foot of dirt is about 100 pounds. To fill a ton, 20 would be needed, but to fill a cubic yard, 27 would be needed. As such, a ton of dirt would only fill about .74 cubic yards.
133.33 cubic yards, that's 400 feet
None because it's a hole but 6 cubic yards of dirt will fill it up.
You also need to specify the average depth.(And by "yards" we assume you mean cubic yards).
It will take 800 cubic yards 1/3 compaction.
You will need 20 cubic yards of dirt, which is 2 loads in a tandem dump truck.
how much sand and other humous is in the dirt ??
It depends on whether the dimensions given are in feet or yards or metres or some other unit.
A yard of dirt is 3ft x 3ft x 3ft, or 27 cubic ft. The hole you need to fill is 8ft x 4ft x 1ft, or 32 cubic ft. You'll need 32/27th yards of dirt, or about 1.19 yards of dirt. Call it a yard and a half if you want to account for settling.
When you buy yards of dirt you are really buying cubic yards. So change your dimensions to yards and multiply together; 10 x 10 x 1.33 = 133 cubic yards. So you would buy 133 yards of dirt.
You are mixing volume (square yard) and area (length x width). How deep do you want the dirt? One foot deep you need about 80 square yards of dirt.