A computer installation is made on account to Systems, Inc. for $1,950.00 and 1 SVR-5699 is sold for $2,200.00; 2 DT-214 for 552.00 each; 2 MON-5478 for 107.00 each; 2 PRN for $225.00; sales tax rate is 8.25% and is charged on both sales and service, as this corporation is in Kansas, and that is the law in the state of Kansas Perpetual FIFO (First-In, First-Out) method is used to calculate cost of goods sold