26ft by 28ft by 4inches thick equal how many yard?

Answer 1

None, since there can be no conversion.
A yard is a measure of length in 1-dimensional space while 26ft by 28ft by 4inches is a measure of volume in 3-dimensional space. The two measure different characteristics and, according to the most basic principles of dimensional analysis, any attempt at comparisons or conversions between the two are fundamentally flawed.

Answer 2

To convert inches to yards, divide by 36 since there are 36 inches in a yard. So 4 inches divided by 36 equals 0.11 yards. Thus, a surface area of 26ft by 28ft by 4 inches thick is equal to approximately 10.89 cubic yards in volume.