What is the first thing you need to determine in order to find the average?

To find the average, the first key step is to determine the total sum of the items involved. Understanding this is crucial because the average is calculated by dividing the total sum by the number of items. Without knowing the total sum, one cannot accurately compute the average.

The other options, while relevant in different contexts, do not serve as a foundational step in finding the average. For instance, knowing the number of items is important but comes after you have determined the total sum. The highest and lowest values may provide additional insights into the data set, but they are not directly involved in calculating the average. Thus, starting with the total sum establishes the basis for any further calculations required to derive the average.