单选题
The following ten observations are a sample drawn from an approximately nomlal population:
| Observation | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Value | -31 | -14 | 3 | -18 | 34 | 20 | -6 | 9 | 7 | -16 |
The sample standard deviation is closest to:
【正确答案】
C
【答案解析】
The sample mean is calculated as follows:
where
Xi is the value of the ith observation and
n is the number of observationsin the sample.
The sample variance is:
The sample standard deviation is the (positive) square root of the sample variarce:
