Substantive procedures, accounting estimates Your client, Stereo Sounds Ltd (SS), manufactures mini hi-fi systems. The company has a year-end of 30 June 205. In December 20X4, SS changed its manufacturing process to make its product more reliable. Because of this increased reliability, the company decided to increase the warranty on its products from 3 years to 5 years in relation to all sales made from 1 January 205. From management's review of warranty claims relating to the new products, it was noted that claims were down by about 20% compared with the old product. Management made an estimate of the provision for warranty of $4000000 for 30 June 205, up from $3500 000 for the previous year. Question 17 Required a) What are the main audit assertions that you should consider for this part of the audit for SS? Describe the types of substantive procedures you would perform to cover these assertions. (10 marks) b) Discuss any special risks in auditing provisions for warranty (and in auditing SS's provision for warranty, in particular). (10 marks)