问题如下：
Selected data on Manager C’s portfolio, which contains three assets, is presentedin Exhibit 1.
Based on Exhibit 1, the proportion of Manager C’s total portfolio variance con tributed by Asset 2 is closest to:
选项：
A.0.0025
0.0056
0.0088
解释：
B is correct. The contribution of an asset to total portfolio variance equals the summation of the multiplication between the weight of the asset whose contribution is being measured, the weight of each asset (xj), and the covariance between the asset being measured and each asset (Cij), as follows:
The contribution of Asset 2 to portfolio variance is computed as the sum of the following products:
和课件246页不一样，也是说的contributed by 课件上要除以R的平方，和前面的解答不一致的原因？
