2012 · Q98
The mean of 100 values is 45. If 15 is added to each of the first forty values and 5 is subtracted from each of the remaining sixty values, the new mean becomes:
Elementary MathematicsStatistics
- A45
- B48
- C51
- D55
Explanation
Net change +600-300 = +300 over 100 values, so mean rises by 3 to 48.