- CFA Exams
- CFA Level I Exam
- Topic 1. Quantitative Methods
- Learning Module 1. Rates and Returns
- Subject 2. Rates of Return
CFA Practice Question
If a teacher computes the mean for a set of test scores and then subtracts this mean from each score, the sum of the resulting set of different scores will equal ______.
B. the mean
C. n times the mean
A. zero
B. the mean
C. n times the mean
Correct Answer: A
User Contributed Comments 5
| User | Comment |
|---|---|
| udhay | Can some one explain this please. |
| VikramJ | Not sure why this is the case either. But I just made up an example. Let's say your set is [1,2] with mean 1.5. Subtract 1.5 from each value and you have -0.5 and 0.5 which equal 0.. |
| 2014 | Sum of deviations from mean is zero. (4,5,6) 15/3 = 5 4-5= -1 5-5=0 6-6=1 +1-1= 0 |
| msk500 | Good explanation, 2014 |
| cosmos1994 | 1,2,3 mean is 2 new set -1,0,1 >> -1+0+1=0 |