Charles Lackey can also improve the yield by purchasing a new blender. The new blender will mean an increase in his investment. This new blender will mean an increase in his costs of $$100$ per month, but he will achieve the same new output $($an increase to $1,875\mathrm{.}00)$ as the change in labor hours.

a$)$ Current productivity for $640$ work hours $=$ loaves$/$dollar $($round your response to three decimal places$).$

If Charles chooses to increase the number of work hours to $800$ in order to emplop the new oven loading technique, then the productivity is$=$ loaves$/$dollar $($round your response to three decimal places$).$

b$)$ If Charles instead chooses to purchase a new blender $($while holding labor constant at $640$ hours at $$8$ per hour$),$ then the productivity is $=,$ loaves$/$dollar $($round your response to three decimal places$).$

c$)$ By adding manpower, the percentage increase in productivity is $,\%($enter your response as a percentage rounded to two decimal places and include a minus sign if necessary$).$

By purchasing a new blender $($while holding labor constant at $640$ hours at $$8$ per hour$),$ the percentage increase in productivity is $\%($enter your response as a percentage rounded to two decimal places and include a minus sign if necessary$).$