(Total fixed costs + Total variable costs) / Total units produced. The cost per unit should decline as the number of units produced increases, primarily because the total fixed costs will be spread over a larger number of units (subject to the step costing issue noted above). Thus, the cost per unit is not constant. For example, ABC Company has total variable costs of $50,000 and total fixed costs of $30,000 in May, which it incurred while producing 10,000 widgets. The cost per unit is: ($30,000 Fixed costs + $50,000 variable costs) / 10,000 units = $8 cost per unit.
Yes, yellow chromated and yellow passivated are the same -- meaning an electroplated finish (usually zinc plating because it's the least expensive) followed by a yellow chromate conversion coating. 1  2. Black finish doesn't imply anything except the color. 2  3. Passivate is a tricky one because it means different things for different substrates.
The passivation process will remove the free iron and other contaminates from the stainless and promote the formation of the beneficial oxide film. I suspect that the pool hand rail and diving board manufactures don't use a passivation step on their stainless steel. It makes some sense given that prior to the advent of SWG (salt pools), there was little need. With the SWG, and thus the salt (electrolyte), it would make more sense to have this done.