5.2 The data below represents the monthly units of an important inventory item purchased by a retailer during 2021. 1 2 3 4 5 6 7 8 9 10 11 12 Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Sales 51 55 54 57 50 68 66 59 67 69 75 73

5.2.1 Use a regression (i.e., trend) analysis to estimate the relationship between time and sales. (7 marks)

5.2.2 Using the equation obtained in question 5.2.1 above, forecast the sales for the first four months of next year. (4 marks)