Particules speed in ideal gasses According to Graham's law, we can calculate de average speed of gasses by using the formula
$$v^2=\frac{3RT}{M}$$
I tried to use this simulation and got these data by keeping same particles amount and increasing the temperature(average speed(m/s) - temperatura(°C)):




T in C
V  in  m/s




27
454


50
480


90
510


130
530


225
590


350
660


425
710


500
740




But, shouldn't be the speed ($v$) a square function of the temperature? ($T=\frac{Mv^2}{3R}$ ) What am I doing wrong?
T in K
$V^2$  in  $\pu{m2 s-2}$




300
206116


323
230400


363
260100


403
280900


498
348100


623
435600


698
504100


773
547600




These are proportional.