1 The presence of a substance and the amount of that substance. 2  Thus, an assay may be done for example to determine the level of thyroid hormones in the blood of a person suspected of being hypothyroid (or hyperthyroid). 3  The biological or pharmacological potency of a drug. Thus, an assay may be done for example to determine the level of thyroid hormones in the blood of a person suspected of being hypothyroid (or hyperthyroid). 2  The biological or pharmacological potency of a drug. 3  For example, an assay may be done of a vaccine to determine its potency.
The total cost curve graphically represents the relation between total cost and the quantity of production. This curve can be derived in two ways. One is to plot a schedule of numbers relating output quantity and total cost. The other is to vertically add the total variable cost curve and the total fixed cost curve.he total cost curve is frequently used with a total revenue curve to determine the profit maximizing level of production for a firm. However, this curve is perhaps most important as the basis for deriving the average total cost curve and the marginal cost curve.
If one assumes that the unit variable cost is constant, as in cost-volume-profit analysis developed and used in cost accounting by the accountants, then total cost is linear in volume, and given by: total cost = fixed costs + unit variable cost * amount.ne can decompose total costs as the sum of fixed costs and variable costs. In the Cost-Volume-Profit Analysis model, total costs are linear in volume. The total cost curve, if non-linear, can represent increasing and diminishing marginal returns.