On December 31, 2017 a physical count of supplies inventory reveals $1, 200 on Amount of the adjustment for supplies used: 1800 A one-year insurance policy was purchased on September 1, 2017 for $2, 400. Amount of the adjustment for insurance used: Equipment was purchased on January 1, 2016 for $18,000. It has a useful life of salvage value of $3,000. Cooperative Company uses the straight line method for calculation. Amount of the adjustment for depreciation