Can you explain the process for solving this general accounting question accurately?

The following standards for variable overhead have been established for a company that makes only one product: - Standard hours per unit of output: 5 hours Standard variable overhead rate: $18.00 per hour The following data pertain to operations for the last month: - Actual hours: 9,000 hours - Actual total variable overhead cost: $162,000 - Actual output: 2,000 units What is the variable overhead rate variance for the month