Which statement defines the mean of a data set?

• A. The middle value when data are arranged in order
• B. The sum of all values divided by the number of values
• C. The difference between the maximum and minimum values
• D. The value that occurs most often

Answer: (B)

Mean is a way to describe the center of a data set that uses every value. You find it by adding all the numbers together and then dividing by how many numbers there are. This gives a single representative value that reflects the overall total. For example, with the values 2, 4, and 6, the sum is 12 and there are 3 values, so the mean is 12 divided by 3, which equals 4.

The middle value when data are ordered is the median, which can differ from the mean if the data are skewed. The difference between the maximum and minimum values is the range, which measures how spread out the data are, not the center. The value that occurs most often is the mode, which identifies the most frequent observation.