Which statement expresses how to compute the mean of a set of numbers?

• A. The sum of all values divided by the number of values.
• B. The product of all values divided by the number of values.
• C. The sum of the largest and smallest values divided by 2.
• D. The maximum value minus the minimum value.

Answer: (A)

To compute the mean of a set of numbers, add all the values together and then divide by how many values there are. This gives the average value that represents the center of the data. For example, with numbers 3, 7, and 9, the sum is 19 and there are 3 values, so the mean is 19/3 ≈ 6.33. The other descriptions don’t produce the mean: multiplying all values and then dividing by the count isn’t the standard average; taking only the largest and smallest and averaging them ignores most data; and subtracting the minimum from the maximum measures the range, not the typical value.