A corporation produces mini$-$widgets. The variatle expenses are $$1\mathrm{.}24$ per mini$-$widget, and the fixed expenses are $$142,900.$ a$.$ What is the total cost to produce $1$ mini$-$widget? $$142\mathrm{.}901\mathrm{.}24$

b$.$ What is the total cost to produce $20,000$ mini$-$widgets? $$167,700$

c$.$ Express the expense function algebraically. $,e=142,900+1\mathrm{.}24q$

d$.$ What is the slope of the expense function?

e$.$ If the slope is interpreted as a rate, give the units that would be used.