The fixed and variable costs for three potential manufacturing plant sites for a rattan chair weaver are shown SiteFixed Cost Per Year $1$ Variable Cost per Unit $$11\mathrm{.}00$ $$7\mathrm{.}00$ $$500$ $$1,000$ $ $1,70023$ $ $4\mathrm{.}00$ a$)$ After rounding the numbers to the nearest whole number, site $1$ is best below $125$ units. After rounding the numbers to the nearest whole number, site $2$ is best between and units After rounding the numbers to the nearest whole number, site $3$ is best above units. b$)$ If the demand is $200$ units, then the best location for the potential manufacturing plant is