NO.PZ202306050200000301
问题如下：
The fund’s standard deviation of returns over the 10 years is closest to:
选项：
A.
2.40 percent
B.
2.53 percent.
C.
7.58 percent.
解释：
B is correct. The fund’s standard deviation of returns is calculated as follows:
The standard deviation is the square root of the sum of the squared deviations,
divided by n − 1:
怎么区分要求的是Sample还是population？
