Excell Technologies is a fairly large IT products distributor and retailer, selling computer equipment, WIFI accessories and licensed software commonly used by business corporations and individuals. Six years ago, it secured the distributorship of a particular laptop brand known as Speedy Gonzales. With an affordable price, ultra-high CPU processing speed, unique colour tones coupled with a razor-thin appearance and light-weight, the brand quickly raced ahead of competing products. Sales were climbing steadily but showed signs of decline in the last three years. As the Marketing Manager of Excell Technologies, you have been tasked by your GM to study the sales trend of the Speedy Gonzales brand of laptops before he meets you to discuss measures to stimulate demand. Your assistant, Chris Chia, retrieved the quarterly sales of the Speedy Gonzales laptop for the last 6 years. The sales data in hundreds of units sold (regardless of the laptop specifications) are presented below:

(a) For the coming discussion, your GM has also requested for the forecasts for Year 7 as an indication of the current sales trend. (i) By plotting an appropriate graph, identify any patterns that may be apparent in the sales data for the last 6 years. (Graph: 2 marks; Data Analysis: 5 marks)

(ii) Suggest a method for determining the projections of sales for Year 7 and justify the method of forecasting to be used. (Forecasting method: 1 mark; Justification of method: 2 marks)

(iii) Study carefully the sales data of Speedy Gonzales laptops. Indicate the appropriate data range to be used for forecasting the sales for Year 7? Explain your choice of the data range. (Choice of data range and reasons: 4 marks)

(iv) Solve the sales of the Speedy Gonzales brand of laptops for the 4 quarters of Year 7, showing clearly each step of the method used with supporting samples of calculations. Round up all calculations to 4 decimal places. (Forecasting calculations: 11 marks; Forecasts for Year 7: 4 marks)

(v) Identify three (3) possible factors, which may affect the accuracy of forecasts for the Speedy Gonzales laptop sales. (Forecasting errors: 6 marks)

Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Quarter 1 51.88 49.67 54.26 60.48 62.495 57.26 Quarter 2 53.55 52.28 59.36 65.12 64.88 61.37 Quarter 3 47.26 50.31 57.65 60.24 60.11 55.33 Quarter 4 50.47 54.77 60.04 63.05 64.49 58.72