One-tail or two-tail

CFA Level III
#1

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?

#2

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.

#3

idreesz Wrote: ------------------------------------------------------- > 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

#4

I thought quality control charts were two tail, given that the confidence intervals are above and below the line.

#5

Use one tail

#6

quality control charts - two tail

#7

so half voted 1 tail, halft voted 2 tails :frowning:

#8

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.

#9

VAR one tail QC two tail positve @negative value

#10

QC is two tail. I was wrong.