In a network, for nodes of degree 

$k=4$, the conditional degree distribution of their neighbors is given by:

$k'$	$P(k' \mid 4)$
1	0.1
2	0.3
3	0.4
5	0.2

What is the value of $k_{nn}(4)$, i.e., the average degree of the neighbors of nodes with degree 4?

$k_{nn}(k)=\sum_{k'} k'P(k'\mid k)$

Alternatives:

A) 2.7
B) 2.9
C) 3.1
D) 3.4
E) None of the above.

Original idea by: Aneglica Santos