A series has the values 8, 12, 10, 14 and 18 for five years. What is the first centred 4-year moving average?

Explanation

1. 01

   The 4-year moving averages are $\frac{44}{4} = 11$ and $\frac{54}{4} = 13.5$; each falls between two years.

2. 02

   Centring averages them in pairs: $\frac{11 + 13.5}{2} = 12.25$, placed against the third year.