Identify whether each of the following is best described as a fixed, variable, or mixed cost with respect to product units. O Answer is complete but not entirely correct. 1. Rubber used in making tennis balls. 2. Depreciation expense of warehouse. 3. Hourly wages of assembly-line worker. 4. Administrative assistant wages. Mixed Fixed Variable Variable 5. Milk used in making ice cream. 6. Electricity used in factory building. 7. Cameras used in making smartphones. Mixed Mixed Variable