Mackintosh recognized warranty expense equal to five percent of net sales revenue generated on the sale of its newest product. One year after introducing the new product, Mackintosh determines that significantly fewer units than predicted were returned by customers for repair or replacement and that this justifies an accounting change. Mackintosh should account for this change Multiple Choice prospectively. o retrospectively. by restating prior years' financial statements. o ignoring the revised estimate. Bertram Inc. purchased new state-of-the-art equipment. Its previously used equipment, which was recently retired, was depreciated over a useful (service) life of ten years. The firm's accounting manager continued depreciating the new equipment over a ten-year useful life. Two years after acquisition, an audit reveals that a five to six-year useful life would have been more appropriate. Addressing this issue represents a Multiple Choice change in accounting principle. change in accounting estimate. change in entity. correction of error