A diffusion couple of two metals, A and $B,$ was fashioned as shown:

After a $730$ hour heat treatment at $1080C$ the concentration of A is $3\mathrm{.}5wt\%$ at the $4\mathrm{.}0$ mm position within

Metal B$.$ At what temperature $($in Kelvin$)$ must the diffusion couple need to be heated to produce this same

concentration at a $2\mathrm{.}4$ mm position after $730$ h $?$ The preexponential and activation energy values for the

diffusion of $A$ in $B$ are $4\mathrm{.}1{10}^{-6}\frac{m^2}{s}$ and $264k\frac{J}{m}ol,$ respectively.