For the distribution with X values and frequencies: 4 with 1, 3 with 2, 2 with 4, 1 with 2, what is ΣX?

For the distribution with X values and frequencies: 4 with 1, 3 with 2, 2 with 4, 1 with 2, what is ΣX?

• A. 16
• B. 20
• C. 24
• D. 28

Answer: (B)

The sum of X values across all observations is found by weighting each value by how often it occurs and then adding those products. Multiply each value by its frequency: 4×1 = 4, 3×2 = 6, 2×4 = 8, and 1×2 = 2. Add them together: 4 + 6 + 8 + 2 = 20. So ΣX = 20. (Total observations are 1+2+4+2 = 9, so the mean would be 20/9 ≈ 2.22 if you need it.)

The sum of X values across all observations is found by weighting each value by how often it occurs and then adding those products. Multiply each value by its frequency: 4×1 = 4, 3×2 = 6, 2×4 = 8, and 1×2 = 2. Add them together: 4 + 6 + 8 + 2 = 20. So ΣX = 20. (Total observations are 1+2+4+2 = 9, so the mean would be 20/9 ≈ 2.22 if you need it.)