A moving average using 15 points having weights 
,
,
,
3, 21, 46, 67, 74, 67, 46, 21, 3, 
, 
, and 
. It is sometimes used by actuaries.
Spencer's 15-Point Moving Average
See also
Moving Average, Spencer's FormulaExplore with Wolfram|Alpha
References
Kenney, J. F. and Keeping, E. S. Mathematics of Statistics, Pt. 1, 3rd ed. Princeton, NJ: Van Nostrand, p. 223, 1962.Referenced on Wolfram|Alpha
Spencer's 15-Point Moving AverageCite this as:
Weisstein, Eric W. "Spencer's 15-Point Moving Average." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Spencers15-PointMovingAverage.html