A process for molding transparent cups from polystyrene has been optimized to run at

$150C$ with a viscosity of $=2$kPa$*s.$ An error in the polymerization led to an increase in

molecular weight of the PS from $60000gmo{l}^{-1}$ to $90000gmo{l}^{-1}$ for this batch. For PS$,$

$T_g=100C,C_1=13\mathrm{.}7,$ and $C_2=50C.$ At what temperature should the molding process

occur for the new batch? $($HINT: for these samples, viscosity increases dramatically with

molecular weight, $M^{3\mathrm{.}4})$