Japan Company produces lamps that require $3$ standard hours per unit at an hourly rate of $$11\mathrm{.}20$ per hour. Production of $4,700$ units required $14,520$ hours at an hourly rate of $$10\mathrm{.}90$ per hour. Enter favorable variances as negative numbers.

$($a$)$ Determine the direct labor rate variance. $fill in the blank $1$

$($b$)$ Determine the direct labor time variance. $fill in the blank $3$

$($c$)$ Determine the cost variance.