Mountain View Hospital (MVH) has adopted a standard cost accounting system for evaluation and control of nursing labor. Diagnosis Related Groups (DRGs), instituted by the U.S. government for health insurance reimbursement, are used as the output measure in the standard cost system. A DRG is a patient classification scheme in which hospitals are regarded as multiproduct firms with inpatient treatment procedures related to the numbers and types of patient ailments treated. MVH has developed standard nursing times for the treatment of each DRG classification, and nursing labor hours are assumed to vary with the number of DRGs treated within a time period. The nursing unit on the fourth floor treats patients with four DRG classifications. The unit is staffed with registered nurses (RNs), licensed practical nurses (LPNs), and aides. The standard nursing hours and salary rates and actual numbers of patients for the month of May were as follows:

What is the labor of RN price variance?