4) SP Ltd is considering computerising its purchasing, delivery and stock control system. With computerisation, the company expects to save $1,000 yearly in inventory costs. The investment in the computer software is estimated to be $4,000. The effective life span of the software is eight years. Depreciation is charged using the straight line method. The rate of company taxation is 20% while the company's cost of financing is 12% per annum a) Compute the net present value of the new computerised inventory system b) Briefly explain whether it is a worthwhile investment. a) b)