In my book it is given that:
The general form of the Grahams Law of Diffusion can be stated as follows when one or all of the parameters are varied: $$\text{rate} \propto \frac{PA}{\sqrt{TM}},$$ where $P$ - pressure, $A$ - area of the hole, $T$ - temperature, $M$ - Molecular weight.
How can rate be inversely proportional to the square root of temperature? I feel that on increasing temperature it must increase, but how can the rate decrease? Is the formula in my book correct or incorrect?