Consider a wing in a high$-$speed wind tunnel. At a point on the wing, the velocity is $900$ ft$/$s$.$ The test section flow is at a velocity of $600$ ft$/$s with a pressure and temperature of $1$ atm and $505$R$,$ respectively. If the test section flow velocity is reduced to $100$ ft$/$s$,$ what will the pressure coefficient become at the same point on the wing?

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The pressure coefficient after the change in velocity at that point is $.$