What is the maximum value of the function $f ( x ) = 1 + \left( \frac { 1 } { 3 } \right) ^ { x - 1 }$ on the closed interval $[ 1,3 ]$? [3 points]\\ (1) $\frac { 5 } { 3 }$\\ (2) 2\\ (3) $\frac { 7 } { 3 }$\\ (4) $\frac { 8 } { 3 }$\\ (5) 3