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

The mean, often referred to as the average, is calculated by first summing all the individual values in a set and then dividing that total by the number of values present in the set. This method provides a central measure that summarizes the data, allowing for an understanding of its overall trend. It is a fundamental statistical concept that represents the midpoint of a data set in a manner that accounts for all data points equally.

The other options present methods that do not yield the mean. For instance, simply summing all values and multiplying by the number of entries does not reflect the mathematical process for finding an average. Average calculation based on only the highest and lowest values ignores the contribution of all other values, leading to a misleading representation. Lastly, summing the squares of values pertains to variance or standard deviation calculations rather than to the determination of the mean. Thus, the correct formula emphasizes appropriately dividing the total sum by the count of values to achieve a representative average of the dataset.