A linear program and its final simplex table are given below:

MaxZ$=3x_1+5x_2$

Subject to:

$x_{1}4$

$2x_{2}12$

$3x_1+2x_{2}18$

$x_1,x_{2}0$

Final Simplex Table

$($i$)$ Compute the range of optimality for the coefficient of ${?}^{x_1}.$

Write your answers into the following boxes $(2$ marks$)$:

$C_{x_1}$

$($ii$)$ Compute the range of feasibility $($right$-$hand$-$side values$)$ for

Constraint $1.$

Write your answers into the following boxes $(2$ marks$)$:

$b_1$ Show details of computation please