One tailed z values memorization values

stronger

Should I memorize these for the exam, the focus seems to be memorizing the 2 tailed z values

one tailed:

90% 1.28
95% 1.65
99% 2.33

ramdabom

Pretty much if it's in the curriculum you should KNOW it. If you hypothesize in your dreams the critical points should be available from memory.

ajpheif16

If they don't tell you directly which test to use you should be able to infer based on the null+alternative hypothesis: does not equal vs. great/less than.

pacmandefense

Yes, questions could be pointing to both 1-tail or 2-tail tests. So, it will be good to memorize standardized z values for both for mosty used confidence intervals. (90, 95 and 99)

But most common 1-tail z characteristic asked for is at 95% confidence, which is same as that for 2-tail at 90% confidence. (i.e. 1.65). And you will be expected to know it as they will not be providing its value in the question.

I dont remember having to use 1-tail value for 90% or 99% in CFA exam or in any practice questions though.