c. During the past month, 2,300 hours of labor time were recorded in the lab at a cost of $25,185. d. The lab's variable overhead cost last month totaled $18,170. Valley View Hospital has never used standard costs. By searching industry literature, however, you have determined the following nationwide averages for hospital labs: Plates: Three plates are required per lab test. These plates cost $2.25 each and are disposed of after the test is completed. Labor: Each blood test should require 0.6 hours to complete, and each smear should require 0.30 hours to complete. The average cost of this lab time is $11.50 per hour. Overhead: Overhead cost is based on direct labor-hours. The average rate for variable overhead is $7.40 per hour. Required: 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?