Hi folks, It’s me again. I have written in my notes that Standard Error of the Estimate is Unexplained variation/n-2 ^1/2. I believe I got that off of a practice exam answer. I know that the official formula for SEE squares the errors of the regression line. However, is the formula above correct? The unexplained variation is not squared, so I’m a little confused? Thanks.
the formula above is correct --> (SSE/n-2)^0.5 = SEE. no clue how or why that is…I just memorized it…this is probably a Joey question.
I’ll just try to list down how my neurons remember this junk… (it’s just a correlation technique, that worked for me…) ********* The sum of squared vertical distances between the actual point on the scatter plot and the estimated point on the regression line is called the Sum of Squared Errors (SSE) no we start correlating things… what was variance?? = the square difference of actual values from the mean values What’s standard Error (the one that we use in Hypothesis)?? S.E. = SQRT(variance/n-1) = SQRT(STD/ n-1) why this n-1 ?? = probably to make it an unbiased error estimator… now think on the similar lines… SEE = Standard Error of Estimates = SQRT(variance/n-2) = SQRT(SEE/n-2) why this n-2 ?? = probably to make SEE an unbiased error estimator I think we need Joey on this… I am giving you an engineers perspective - Dinesh S
delhirocks Wrote: ------------------------------------------------------- > the formula above is correct --> (SSE/n-2)^0.5 = > SEE. > > no clue how or why that is…I just memorized > it…this is probably a Joey question. I’m sure it’s true, but I have a cold and I’m stoned on codeine and DXM. Got little spots between me and the monitor.
Yep. The CFA practice test #3, Question 14, gives the answer to the SEE as unexplained variation/n-2 raised the 1/2. So, I’m guessing that the really long equation for SEE just means that. Maybe in the really long equation you have to square the numerator because the unexplained variation is multiplied by X. I don’t know. There is so much crap in this CFA test! Isn’t there?
Dude! I just got it! UNEXPLAINED VARIATION IS ACTUAL VALUE FOR Y-PREDICTED VALUE FOR Y SQUARED! So, all in all, the CFA Practice exam is correct. SEE is the Unexplained variation/n-2 raised to 1/2.