The answer is: [C]: standard deviation ..
___________________________________
Step-by-step explanation:
___________________________________
However, note that the mean of a sample from a normal population (that is, a type of "standard deviation" known as "standard deviation from a sample mean", is an "unbiased estimator" of the "population mean".
We shall represent the "sample mean" as: x̅ ;
(pronounced: "x-bar"; that is; "ex-bar"); this is the usual symbol used;
We shall represent the sample size as "n" ;
(This is the usual variable used; note that
"n" is a numeric value).
__________________________________________________________
The standard deviant from the sample mean:
(n * x̅) / (n + 1) is a "biased estimator of the mean" that becomes "unbiased" as the sample size increases; since as "n" increases in values; the value of the entire entire expression becomes smaller (i.e the standard deviation becomes smaller.
___________________________