x \(\alpha\) \(\frac{1}{y}\) .........(1) x = k x \(\frac{1}{y}\) .........(2) When x = 2\(\frac{1}{2}\) = \(\frac{5}{2}\), y = 2 (2) becomes \(\frac{5}{2}\) = k x \(\frac{1}{2}\) giving k = 5 from (2), x = \(\frac{5}{y}\) so when y =4, x = \(\frac{5}{y}\) = 1\(\frac{1}{4}\)