The standards for one case of liquid weed killer are as follows:

Direct materials

Direct labor

Variable overhead $($based on

machine hours$)$

$9\mathrm{.}00$ pound @ $$11\mathrm{.}25$ per pound

$5\mathrm{.}40$ hour@$$24\mathrm{.}00$ per hour

$1\mathrm{.}80$ hour@$$8\mathrm{.}25$ per hour

During the week ended May $6,$ the following activity took place:

$5,848$ machine hours were worked.

$31,088$ pound of raw material were purchased for inventory at a total cost of $$356,890.$

$3,420$ cases of finished product were produced.

$30,622$ pound of raw material were used.

$18,062$ labor hours were worked at an average rate of $$24\mathrm{.}38$ per hour.

$$46,550$ actual variable overhead costs were incurred.

Required:

Calculate each of the following variances.

Note: Do not round intermediate calculations. Indicate the effect of each variance by selecting $"$F$"$ for favorable, $"$U$"$ for

unfavorable, and "None" for no effect $($i$.$e$.,$ zero variance$).$

a$.$ Price variance for raw materials purchased.

b$.$ Raw materials usage variance.

c$.$ Direct labor rate variance.