2
[16W]Given \(x_ 1,\ldots x_ kβ β^ n\) , given \(t_ 1,\ldots t_ kβ₯ 0\) with \(t_ 1+\cdots + t_ k=1\), the sum
\[ x_ 1 t_ 1+\cdots + x_ k t_ k \]
[16W]Given \(x_ 1,\ldots x_ kβ β^ n\) , given \(t_ 1,\ldots t_ kβ₯ 0\) with \(t_ 1+\cdots + t_ k=1\), the sum