Sam is a director of a company currently undergoing an audit. The auditors have informed Sam that his company has some issues with accounting policies and accounting estimates. For each of the scenarios given below you have to advise Sam whether it is a change in accounting policy or a change in accounting estimate. Provide brief reasons.

1. The useful life of depreciable plant is determined as being 5 years. 2. Sams company depreciates non-current assets. 3. Sams company uses straight-line depreciation. 4. Sams company determines that it will calculate its warranty provision using past experience of products returned for repair under warranty. 5. The current years warranty provision is calculated by providing for 3% of current year sales, based on last years warranty claimed amounting to 3% of sales.