We know that the decline is 4% each year from 2009 to 2015.
The enrollment was 1575 in 2009, let's multiply this by 4% to find 2010, and so on until we get 2015.
![\begin{gathered} 1575\cdot0.04=63 \\ 1575+63=1638 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/vypvc7dz4grp07059iv90qkfxlfp2nj0r1.png)
So, the enrollment was 1638 in 2010.
![\begin{gathered} 1638\cdot0.04=65.52 \\ 1638+65.52=1703.52 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/6ihwhr3arwkda60fodwe6o8hbiamqycyjh.png)
The enrollment was 1703.52 in 2011.
![\begin{gathered} 1703.52\cdot0.04=68.1408 \\ 1703.52+68.1408=1771.6608 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/vigzhcg2cmbpovj4l1s1m33ulobm5lvgx5.png)
The enrollment was 1771.6608 in 2012.
![\begin{gathered} 1771.66080\cdot0.04=71 \\ 71+1771.66080=1842.66 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/q37zddyxhnyjw71fpsobftfewv32lr6urr.png)
The enrollment was 1842.66 in 2013.
![\begin{gathered} 1842.66\cdot0.04=73.71 \\ 1842.66+73.71=1916.37 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/uaydfvhu3ek15j7puxypwvr8jpfebu5806.png)
The enrollment was 1916.37 in 2014.
![\begin{gathered} 1916.37\cdot0.04=76.65 \\ 1916.37+76.65=1993 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/fkijkzbromy9iwjh3xuno2f6dzc0g118wo.png)
Hence, the enrollment was 1993 in 2015.