define a measure on A the power set

Question

I was asked the following:

Let $X$ be any set and $A = P(X)$ be the power set of $X$. Let $x_1,\ldots,x_n$ be distinct points in $X$ and let $α_1, \ldots , α_n$ be positive real numbers, define the measure on A:

Am I correct in saying:

$μ = α_1δx_1 + α_2δx_2 + \cdots + α_nδx_n$ defines a measure on $A$?