A smartphone cost a retailer $860.00 less a series discount of 31.5%, 7%. The regular selling price is $829.00. The dealer's overhead is 18% of the regular selling price. The smartphone did not sell for the regular selling price, so the retailer applied a mark down and sold the phone for $678.75. (8 marks) a) Determine the amount of markup (in dollars) the dealer applies to the smartphone to sell at the regular price of $829.00. b) What is the markup rate based on regular selling price? c) What was the rate of markdown? I d) What was the operating profit or loss when the retailer sold the phone for $678.75 (the mark down price)?