Portfolio weighting, where to use w and (1-w) reading, number, likely

thisisbrianly

How do you know which factor to multiply by “w’ and which to multiply by “1-w”
Either my algebra is goofy (highly likely) or these really do come out differently depending where you put the w or 1-w
Specifically, I’m looking at things like number 15 CFAI text, page 465, reading 64 or #9

ASSet_MANagemen

I figured it was just my algebra…thanks

hw0799

5w+13(1-w) = 17
-8w+13=17
-8w = 4
w = -0.5 in rf , so (1-w) = 1.5 in the 13 return portfolio
5(1-w)+13w = 17
5+8w = 17
8w=12
w=1.5 in 13% return
(1-w)=-0.5 in the rf
No difference…

MonkeyBusiness

It should be mentioned in the question how much to invest in each stock or portfolio. Could you let me know which volume you are referring to?