标题: One-tail or two-tail [打印本页] 作者: pawn 时间: 2011-7-11 19:32 标题: One-tail or two-tail
Hi,
VAR mean-variance approach, one tail or two tail?
Quality control chart? H0: manager adds no value, blar blar blar.... one tail or two tail?作者: bkballa 时间: 2011-7-11 19:32
Var - one tail - used to measure downside risk
Quality control - one tail - company making statistical checks on the quality of its medical products is only interested in whether their product has fallen significantly below an acceptable standard.作者: dyga 时间: 2011-7-11 19:32
idreesz Wrote:
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> Var - one tail - used to measure downside risk
>
> Quality control - one tail - company making
> statistical checks on the quality of its medical
> products is only interested in whether their
> product has fallen significantly below an
> acceptable standard.
Hi
Don't you think the quality control chart looks two-tail?
thx作者: Roflnadal 时间: 2011-7-11 19:32
Var - one tail
QC chart: two tail since the null hypothesis is that the manager does not add any value: expected return - benchmark return= 0, so there is an upperbound and a lowerbound for the confidence band which narrows over the years.
