2022 · Q63
The sum of deviations of a set of n values measured from 50 is - 10 and the sum of deviations of the values measured from 46 is 70. What is the mean of the values?
Elementary MathematicsStatistics
- A48.5
- B49.0
- C49.5
- D50.0
Explanation
Σxᵢ = 50n−10 = 46n+70 gives n = 20; the mean is (50×20−10)/20 = 49.5. Indeed, shifting the reference point by 4 raises the deviation sum by 4n, so 70−(−10) = 4n. The keyed option is C.