Given that ∑fx = 340 and N = 20, find the arithmetic mean.

Analyze the question: You are given the sum of (frequency × value), ∑fx = 340, and the total frequency N = 20. You need the arithmetic mean.

Concept: For grouped or frequency data, the arithmetic mean is:

Mean (x̄) = ∑fx / ∑f = ∑fx / N

Solution:

x̄ = 340 / 20

x̄ = 17

Check against the options:

• A. 20 ✗
• B. 17 ✓
• C. 32 ✗
• D. 9 ✗

Tip: In frequency-distribution questions, always divide the total of the fx column by the total frequency. Don't divide by the number of classes. If the numbers divide neatly, like 340 ÷ 20, you can quickly confirm: 20 × 17 = 340. ✔