What is the method for calculating the mean of a data set?

Calculating the mean of a data set involves summing all the individual scores or values and then dividing that total by the number of values. This method gives you an average that represents the central tendency of the data. By using this process, you effectively account for all entries in the data set, ensuring that the result reflects the overall distribution of the scores.

Other methods mentioned, such as identifying the middle value, only apply in finding the median, which represents a different measure of central tendency. Subtracting the lowest value from the highest value gives you the range, which indicates spread but not average, and merely counting the total number of values provides information about size rather than a central measure. Thus, the appropriate choice to determine the mean is indeed to add all the scores and divide by the total number of values.