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\frac{\operatorname{Var}\left(Q^{k}\right)}{\operatorname{Var}(D)} \geq \sqrt{R}-\left[1+\frac{2 \sum_{i=1}^{k} L_{\bar{z}}}{p}+\frac{2\left(\sum_{i-1}^{k} L_{\bar{k}}\right)^{2}}{p^{2}}\right]+(1-\sqrt{R}) \cdot\left[\prod ^ { k } \left(1+\frac{2 L_{i}}{p}+\right.\right.