1. At a depth of $x$ metres, the temperature of the water in an ocean is ${T}^{∘}C$. At depths below $900$metres, $T$ is inversely proportional to$x$.

$T$ is given by

            $T=\frac{4500}{x}$

Work out the difference in the temperature of the water at a depth of $1200$ metres and the temperature of the water at a depth of $2500$metres.