Definition Term A. The way in which total cost behaves or changes, when some measure of activity changes. B. The range of activity over which assumptions about cost behavior hold true. C. A cost that changes in total in direct proportion to changes in activity while the per unit cost remains constant. D. A cost that is fixed over a narrow range of activity and increases multiple times across a relevant range. E. A cost that remains the same in total regardless of the activity level. F. Both the total cost and the cost per unit change with the level of activity. G. A cost that is fixed over a wide range of activity, but increases when a capacity limit is reached. H. The expression of the relationship between total cost and activity expressed as y = a + b(x). I. A visual representation of the relationship between total cost and activity level. J. The use of the two most extreme activity points to determine the variable cost per unit. K. A measure of how well the data is represented by the formula y = a + b(x). L. The difference between sales revenue and variable costs..