=+3-32 KK High–low method, regression analysis OBJECTIVES 4, 5 Rockhampton College has recently opened a restaurant as part of its hospitality major. For the first 10 weeks the manager did not estimate any costs but instead hoped revenues would cover costs. One of the new waiters, who happens to be taking a cost accounting class, suggests that the manager take the past known weekly costs and try to determine a cost equation by relating the cost to the number of customers served. The cost and customer data are as follows:

Week Number of customers per week Weekly total costs of restaurant 1 751 $16 800 2 745 16 597 3 810 17 800 4 833 18 600 5 825 17 900 6 876 19 600 7 855 18 900 8 897 18 500 9 925 20 305 10 910 20 000 The manager gives this information to the waiter, who runs a regression and gets the following equation:

Weekly total restaurant costs = $2453 + ($19.04 × Number of customers per week)

Required 1 Plot the relationship between number of customers per week and weekly total restaurant costs.