16.2 $$ Q{n}(k)=\frac{1}{n}\left((n-1)\times Q{n-1}(k)+v{n}\right) $$ [推导]: $$ \begin{aligned} Q{n}(k)&=\frac{1}{n}\sum{i=1}^{n}v{i}\\ &=\frac{1}{n}\left(\sum{i=1}^{n-1}v{i}+v{n}\right)\\ &=\frac{1}{n}\left((n-1)\times Q{n-1}(k)+v{n}\right)\\ &=Q{n-1}(k)+\frac{1}{n}\left(vn-Q{n-1}(k)\right) \end{aligned} $$ 16.