Hi,I want to prove above unequal that consist of two summation both of this sides.It a formula in Computer Network to control Congestion.The way to prove it is not important, but because I weak in mathematical i want to know all thing about details. More information about Network congestion! is available on below image(Raj Jain Proposal). In fact, finally I want to prove that the numerator is less or equal than denominator. I persist again that I want to know completely detail about the proof steps.
From RMS-AM inequality, $$\sqrt{\dfrac{\sum_{i=1}^n x_i^2}{n}}\geq \dfrac{\sum_{i=1}^n x_i}{n}$$ where $x_i>0 \,\,\,\,\, \forall\,\,\,\,\,i\in \{1,2,\cdots n\}$. Square both sides of inequality and you obtain what is stated in OP.