In calculating mean one should

Step 1: Analyze the question The question asks how the mean (the arithmetic average) is calculated.

Step 2: Explain the concept The mean is a measure of central tendency. The three common measures are:

• Mean: the average of all values
• Median: the middle value when the data is arranged in order
• Mode: the most frequently occurring value

Formula:

Mean = (Sum of all the values) ÷ (Number of values)

or, in symbols, x̄ = Σx / n

Step 3: Evaluate the options

• A. Add the highest and the lowest number: This is not the mean. It is part of finding the mid-range (after dividing by 2).
• B. Divide the highest and the lowest number: This has no meaning as a measure of central tendency.
• C. Divide the sum of the figures by the number of figures: This matches the definition of the mean exactly.
• D. Find the most common number: This is the mode.
• E. Pick any number that has no partner: This has no statistical meaning.

Step 4: Example Find the mean of 4, 6, 8, 10, 12.

• Sum = 4 + 6 + 8 + 10 + 12 = 40
• Number of values = 5
• Mean = 40 ÷ 5 = 8

This confirms the method in option C.

Memory tip: Think of Mean as "Math average": add everything, then share equally (divide by how many there are). Mode = Most common, and Median = Middle.