Let the total number of students be \(9u\) (undergraduate \(7u\), postgraduate \(2u\)).<br><br>
&bull; Undergraduate local = \(\frac{4}{4+1} \times 7u = \frac{4}{5} \times 7u = 5.6u\).<br>
&bull; Undergraduate international = \(\frac{1}{5} \times 7u = 1.4u\).<br>
&bull; Postgraduate local = \(\frac{1}{1+4} \times 2u = \frac{1}{5} \times 2u = 0.4u\).<br>
&bull; Postgraduate international = \(\frac{4}{5} \times 2u = 1.6u\).<br>
&bull; Total local = \(5.6u + 0.4u = 6u\); total international = \(1.4u + 1.6u = 3u\).<br>
&bull; Ratio = \(6u : 3u = 2 : 1\).<br><br>
Final Answer: 2 : 1