5.8 The data in Table 5-8 concern the monthly sales ¯gures of a shop which opened in January 1987 and sells gifts, souvenirs, and novelties. The shop is situated on the wharf at a beach resort town in Queensland, Australia. The sales volume varies with the seasonal population of tourists. There is a large in°ux of visitors to the town at Christmas and for the local sur¯ng festival, held every March since 1988. Over time, the shop has expanded its premises, range of products, and sta®.