I started it but I do not understand how to get the right variable rate. Can someone please help me out and explain how you did it? THANK YOU!

Creating and Using a Cost Formula

Big Thumbs Company manufactures portable flash drives for computers. Big Thumbs incurs monthly depreciation costs of $14,100 on its plant equipment. Also, each drive requires materials and manufacturing overhead resources. On average, the company uses 6,750 ounces of materials to manufacture 4,500 flash drives per month. Each ounce of material costs $3.00. In addition, manufacturing overhead resources are driven by machine hours. On average, the company incurs $27,000 variable manufacturing overhead resources to produce 4,500 flash drives per month.

In your calculations, round variable rate per flash drive to the nearest cent. If required, round final answers to the nearest cent.