Let
X,
X1, … be independent and identically distributed random variables with zero and finite absolute
p-th moment for some
p greater than or equal to two. For each positive integer
n, let
an1, …,
ann be constants. The boundedness of {(
a2n1+…+
a2nn)/
n2/p,
n≥1} is established to be a necessary and sufficient condition for the uniform integrability of {|∑
aniXi/
n1/p|
p,
n≥1}. Conditions are also given for the central limit thorem and the convergence in probability of {∑
aniXi/
n1/p,
n≥1}. An improvement of Thrum's (1987) theorem on the almost sure convergence is obtained. As a result, the moment convergence and its limits are established.
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