中等MATH-STAT-007
Which statement about the standard deviation used in the compulsory part is correct?
A. It is calculated with divisor n, not n − 1✓ 答案
B. It is always larger than the range
C. It can be negative
D. Adding a constant to every datum doubles it
解說
The compulsory-part formula divides the sum of squared deviations by n. A standard deviation is non-negative and need not exceed the range. Adding a constant leaves it unchanged.