The general quadratic model is,
[tex]y=ax^2+bx+c[/tex]
Let us sketch the graph below
From the graph above,
[tex]\begin{gathered} a=-0.015 \\ b=3.75 \\ c=50 \end{gathered}[/tex]
Hence, the model to the data given is
[tex]y=-0.015x^2+3.75x+50[/tex]
Therefore, from the graph given the population in 2050 is 275millions.
