3.
已知椭圆\(C\):\( \dfrac {x^{2}}{a^{2}}+ \dfrac {y^{2}}{b^{2}}=1(a > b > 0)\)的左右焦点分别为\(F_{1}\),\(F_{2}\),若椭圆上一点满足\(P( \dfrac {2 \sqrt {6}}{3},-1)\)满足\(|PF_{1}|+|PF_{2}|=4\),过点\(R(4,0)\)的直线\(l\)与椭圆\(C\)交于两点\(M\),\(N\).
\((\)Ⅰ\()\)求椭圆\(C\)的方程;
\((\)Ⅱ\()\)过点\(M\)作\(x\)轴的垂线,交椭圆\(C\)于\(G\),求证:存在实数\(λ\),使得\( \overrightarrow{GF_{2}}=λ \overrightarrow{F_{2}N}\).