Racing Bicycle Sales Study
A cycle shop recorded the quarterly sales of racing bicycles for the period 2009 to 2011, as shown in Table 15.5. (See Excel file C15.3 – bicycle sales.)
Management Question
Produce a four-period centred moving average for the quarterly sales of racing bicycles sold by the cycle shop during the period 2009 to 2011.
Table 15.5 Quarterly sales of racing bicycles (2009–2011)
2009 | 2010 | 2011 | ||||||||||
Period | Q1 | Q2 | Q3 | Q4 | Q1 | Q2 | Q3 | Q4 | Q1 | Q2 | Q3 | Q4 |
Sales (y) | 17 | 13 | 15 | 19 | 17 | 19 | 22 | 14 | 20 | 23 | 19 | 20 |
The resulting calculations are shown in Table 15.6.