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Japan Company produces lamps that require $2$ standard hours per unit at a standard hourly rate of $$20\mathrm{.}70$ per hour. Production of $6,300$ units required $12,850$ hours at an hourly rate of $$20\mathrm{.}30$ per hour.

What is the direct labor $($a$)$ rate variance, $($b$)$ time variance, and $($c$)$ total cost variance? Enter favorable variances as negative numbers.

a$.$ Direct labor rate variance

b$.$ Direct labor time variance

c$.$ Total direct labor cost variance