Let x and y be the year and production
Here x̄ = 2013
From the normal equaiton na + bΣx = Σy
From Σa + bΣx2 = Σxy b = 
Since Σx 
= 90 and
The fitted straight line trend equation is
y = a + bx : ŷ = 90 + 3x
Trend values : (2010) = 90 + 3(-3) = 81
ŷ(2011) = 90 + 3(-2) = 84.
Similarly all remaining trend values can be compated.
Estimation of production for 2017; x = 4
ŷ (2017) = 90 + 3(4) = 102 Tons.
