$(10$ points$)$ The following standards have been established for a raw material used to

product I$92$:

The following data pertain to a recent month's operations:

Actual material purchased...................... $13,600$ pounds

Actual cost of material purchased.......... $$31,620$

Actual material used in production $.........13,600$ pounds

Actual output....................................... $2,300$ units of product $192$

Actual labor used $7,100$ hours

Actual total labor cost $$57,150$

Required:

a$.$ What is the materials price variance for the month?

b$.$ What is the materials quantity variance for the month?

c$.$ What is the labor rate variance for the month?

d$.$ What is the labor efficiency variance for the month?