# Feynman Probability lecture 6 - probability density graph

I'm trying to understand the 6-7 graph in the Feynman lecture 6 on Probability chapter (6–4) A probability distribution

He says:

"We plot $$p(x)$$ for three values of $$N$$ in Fig. 6–7. You will notice that the “half-widths” (typical spread from $$x=0$$) of these curves is $$\sqrt N$$, as we have shown it should be."

I can't see this in the graph, where are actually the "half-widths"?

For the medium graph labeled "N=40,000" which has 4x the number of samples, the half-width looks to be about 560, or 2x ($\sqrt{4}$x).
For the short graph labeled "N=160,000" which has 16x the number of samples, the half-width looks to be about 1120, or 4x ($\sqrt{16}$x).