Epsilon Enterprise Ltd, a manufacturer of small household appliances, has carried out market research to determine that if a price of 250 is charged for one of its best-selling products, the Shark, demand will be 12,000 units. Epsilon Enterprise has also established that demand will rise or fall by 5 units for every 1 fall/rise in the selling price of the Shark. The marginal cost of the Shark is 80. The formula for Marginal Revenue (MR) = a 2bQ when the selling price P = a bQ, where: P = the price Q = the quantity demanded a = the theoretical maximum price b = change in price/change in quantity Required: (a) Calculate the profit-maximising selling price for the Shark. (13 marks) (b) Discuss any four factors other than price, that can influence the demand for a product or service.