# Math Help - Datamodelling: Sinus function with decreasing amplitude

1. ## Datamodelling: Sinus function with decreasing amplitude

Dear all,
A teacher of mine gave us a data set consisting of following data (see also spreadsheet):

Fish production during the period of 1980 - 2006 (Mass/Year)

(426.8/1980), (470.2/1981), (503.4/1982), (557.3/1983), (564.7/1984), (575.4/1985), (579.8/1986), (624.7/1987), (669.9/1988), (450.5/1989),
(379.0/1990), (356.9/1991), (447.5/1992), (548.8/1993), (589.9/1994),
(634.0/1995), (527.8/1996), (459.1/1997), (487.2/1998), (573.8/1999),
(503.3/2000), (527.7/2001), (566.7/2002), (507.8/2003), (550.5/2004), (426.5/2005), (533.0/2006)

The task is to find a function which approximates this data set. I tried
to plot the data in Excel. This resulted in a graph which resembles a
sinus function with decreasing amplitude (see attachment). I tried to
find a suitable function, without any success. I‘m grateful for every
help.

Kind regards,
Christian