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Please help me in understanding the followign formulae?

Prediction of the Length of the Next CPU Burst

             Pn+1 = a tn +(1-a)Pn 

             This formula defines an exponential average

              Pn stores the past history

              tn contents are most recent information

              the parameter “a “controls the relative weight of recent  and past history of  in our prediction

              If a =0 then Pn +1 =Pn

             That is prediction is constant

              If a = 1 then Pn +1 = tn

              Prediction is last cpu burst

I dont want to learn this.Please provide some logical explanation

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Pn+1 = aTn + (1-a)Pn

I am using two states: previous and next.

In the previous state, we guess the BT Pn and at the time of execution, but it appears that its actual BT was Tn.

So now we use a smoothing factor a which will consider both - our guess as well as the actual BT.

In next state Our expected BT Pn+1 will be given by the formula: Pn+1 = aTn + (1-a)Pn

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