The fixed and variable costs for three potential manu$-$

facturing plant sites for a rattan chair weaver are shown:

SITE

FIXED COST PER YEAR

VARIABLE COST PER UNIT

$1$ $ $500$ $$11$

$21,0007$

$3$

$1,700$

$4$

a$)$ Over what range of production is each location optimal? b$)$ For a production of $200$ units, which site is bes