$1.$ Compute a materials price variance for the plates purchased last month and a materials quantity variance for the plates used last month.

$2.$ For labor cost in the lab:

a$.$ Compute a labor rate variance and a labor efficiency variance.

b$.$ In most hospitals, one$-$half of the workers in the lab are senior technicians and one$-$half are assistants. In an effort to reduce costs, Valley View Hospital employs only one$-$fourth senior technicians and three$-$fourths assistants. Would you recommend that this policy be continued?

$3-$a$.$ Compute the variable overhead rate and efficiency variances.

$3-$b$.$ Is there any relation between the variable overhead efficiency variance and the labor efficiency variance?