3 The variables \(x\) and \(y\) satisfy the equation \(x ^ { n } y = C\), where \(n\) and \(C\) are constants. When \(x = 1.10\), \(y = 5.20\), and when \(x = 3.20 , y = 1.05\).
- Find the values of \(n\) and \(C\).
- Explain why the graph of \(\ln y\) against \(\ln x\) is a straight line.