[Maximum mark: 6] The Marketing Director of Sea World was concerned about the effectiveness of a recent advertising campaign. The Director recorded the advertising cost and the number of tickets sold in the last eight months. The data is shown in the table below and was sorted in ascending order by advertising cost. Advertising cost, 60.51 68.60 74.52 75.11 in thousands USD (=) 75.43 70.34 81.15 82.42 Number of tickets sold, 1.22 1.98 2.19 1.75 2.03 in thousands (y) 1.57 2.38 2.23 Suppose that the number of tickets sold varies linearly with the advertising cost. (a) Find (i) the Pearson's product moment correlation coefficient, r, for this data; (ii) the equation of the regression line y on r. (b) The Marketing Director decides to spend 70000 USD on advertisement next month. Use the equation of the regression line found in part (a) (ii) to estimate the number of tickets to the Sea World sold next month. Round your answer to the nearest hundred. [2]