An assay is an investigative (analytic) procedure in laboratory medicine, pharmacology, environmental biology and molecular biology for qualitatively assessing or quantitatively measuring the presence or amount or the functional activity of a target entity (the analyte). Qualitative assay, i.e. assays which generally give just a pass or fail, or positive or negative or some such sort of only small number of qualitative gradation rather than an exact quantity.
The average fixed cost (AFC) curve will decline as additional units are produced, and continue to decline. The average total cost (ATC) curve initially will decline as fixed costs are spread over a larger number of units, but will go up as marginal costs increase due to the law of diminishing returns.
Average total cost is the total cost per unit of output incurred when a firm engages in short-run production. It can be found in two ways. Because average total cost is total cost per unit of output, it can be found by dividing total cost by the quantity of output.