The Sx and Sigmax that we get on TI BAII Plus is the std devn or the variance. I thought it was std devn and got one question right by taking it as std devn sometime back, but today I was solving a question where in I got to know it is the variance. So, is it variance or std devn? I am talking about the number that we get on STAT modr after we key in data in DATA mode.
it is std deviation, not variance.
sx = sample standard deviation
sigmax = population standard deviation
If you take that question on tracking error, key in the values mentioned into the DATA mode and then switch to STAT mode, the Sx the calculator gives you is same as the value that cfai text computes for variance of thevdata points. They have mentioned that the std devn is sq root of 29.9473, which is what we obtain as Sx on TI BA II Plus. So, effectively the text book does sq root (Sx)
check with cfa institute, definitely an erratum.
29.947 is the std deviation of the active returns, so they are making a mistake, if they have written this.