Which of the following is required to calculate the High-Low Method?

To calculate variable costs using the High-Low Method, the key requirement is to identify the highest and lowest levels of activity. This method helps in analyzing how costs change with variations in activity levels by taking the extreme points of activity and their corresponding costs. By determining these two points, one can compute the variable cost per unit, which is essential for cost estimation and budgeting.

The highest level of activity corresponds to the maximum output or usage, while the lowest level indicates the minimum. The difference in total costs at these levels allows one to isolate the variable component of costs—essentially showing how costs behave in response to changes in activity.

In contrast, knowing total sales revenue, the average cost of production, or the total number of units sold does not provide the necessary data to isolate variable costs effectively using this method. Each of those options relates to overall financial performance or cost structure but does not specifically pinpoint the critical variable-cost dynamics needed for the High-Low Method analysis.