# Portfolio Variance - Explanation for equation : Investments by Zvi Bodie

Source: Investments 10th Edition by Bodie, Zvi. Page 227 Chapter 7

In Equation 7.17, the book breaks the variance into two parts. I can't seem to understand why the 1/n is represented outside the summation part in the first part of the equation. Also, shouldn't there be a single n given that there are n observations representing variance in the covariance table?