A local university is considering changes to its class structure in an effort to increase professor productivity. The old schedule had each professor teaching $5$ classes per week, with each class meeting an hour per day on Monday, Wednesday, and Friday. Each class contained $20$ students.

The new schedule has each professor teaching only $3$ classes, but each class meets daily $($Mon$.-$Fri.$)$ for an hour. New classes contain $50$ students.

Calculate the labor productivity for the initial situation $($students$/$hour$).[$ Select $]["10\mathrm{.}0","5\mathrm{.}25","11\mathrm{.}56","6\mathrm{.}67"]$

Calculate the labor productivity for the schedule change $($students$/$hour$).[$ Select $]["4\mathrm{.}23","12\mathrm{.}56","10\mathrm{.}0","6\mathrm{.}67"]$

What is the change in productivity?$[$ Select $]["38\%","45\%","50\%","25\%"]$