NO.PZ2016062402000036
问题如下：
The measurement error in VAR, due to sampling variation, should be greater with
选项： More
observations and a high confidence level (e.g. , 99%)
Fewer observations and a high confidence level
C.More observations and a low confidence level (e.g. , 95%)
D.Fewer observations and a low confidence level
解释：
Sampling variability (or imprecision) increases with (1) fewer observations and (2) greater confidence levels. To show (1), we can refer to the formula for the precision of the sample mean, which varies inversely with the square root of the number of data points. A similar reasoning applies to (2). A greater confidence level involves fewer observations in the left tails, from which VAR is computed.
