Ниже приведено распределение случайной величины \(\displaystyle X\small.\)

\(\displaystyle x\)	\(\displaystyle -2\)	\(\displaystyle -1\)	\(\displaystyle 0\)	\(\displaystyle 2\)
\(\displaystyle P(X=x)\)	\(\displaystyle k\)	\(\displaystyle 2k\)	\(\displaystyle k\)	\(\displaystyle 2k\)

Чему равно \(\displaystyle k\small?\)

\(\displaystyle k=\)[ ]