Calculus In Parabola

Let $S$be the focus of $y^2 = 4x.$Point $P$等这条曲线上移动,其横坐标是什么increasing at a rate of $4$units per second. Then the rate of increase of the length of projection of $SP$on $x + y =1$when $P$is at $(4,4)$is $\gamma$.

Find $10^3\gamma$to 1 decimal place.