Hi, may I ask what does conditional on X really mean? So X is only equal to one constant, or it is equal to an array of constant, like x=1, x=2, x=3? Really appreciate you putting the videos tgt! All the proofs really help me a lot!
"Conditional on X" means that you know what X is, in other words you have the data. It is indeed an array (or matrix) of constants. "Constant" here is opposed to "random variable".
do you have an example on why E(E(XlY))=E(X) im trying to figure out why it turns out this way. is it like if E(XlY) equals to let say (p) then E(p)=E(E(XlY))=E(p) ?
To see how it works, I would recommend writing the expectation as an integral. Wikipedia calls it "Law of total expectation", so you can also google that. There are many pages about it since it is used in several fields.
Thank you so much. It really helped me.
Hi, may I ask what does conditional on X really mean? So X is only equal to one constant, or it is equal to an array of constant, like x=1, x=2, x=3?
Really appreciate you putting the videos tgt! All the proofs really help me a lot!
"Conditional on X" means that you know what X is, in other words you have the data. It is indeed an array (or matrix) of constants.
"Constant" here is opposed to "random variable".
do you have an example on why E(E(XlY))=E(X) im trying to figure out why it turns out this way. is it like if E(XlY) equals to let say (p) then E(p)=E(E(XlY))=E(p) ?
To see how it works, I would recommend writing the expectation as an integral.
Wikipedia calls it "Law of total expectation", so you can also google that. There are many pages about it since it is used in several fields.