Assume that Nortel manufactures specialty electronic circuitry through a unique photoelectronic process. One of the primary products, Model ZX$40,$ has a standard labor time of $0\mathrm{.}5$ hour and a standard labor rate of $$13\mathrm{.}00$ per hour. During February, the following activities pertaining to direct labor for ZX$40$ were recorded: Direct labor hours used $2,180$ Direct labor cost $$32,000$ Units of ZX$40$ manufactured $4,600$

$($a$)$ Determine the labor rate variance