Ruby Company produces a chair for which the standard specifies $7$ yards of material per unit. The standard price of one yard of material is $$9\mathrm{.}00.$ During the month, $8,400$ chairs were manufactured, using $58,200$ yards at a cost of $$8\mathrm{.}46$ per yard.

Determine the following: Enter favorable variances as negative numbers.

a$.$ Direct materials price variance

$

b$.$ Direct materials quantity variance

$

c$.$ Total direct materials cost variance

$