0
$\begingroup$

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"?

$\endgroup$
0
$\begingroup$

Half-width definition: the with of the graph where it attains half the peak amplitude.

For the tall graph labeled "N=10,000" the half-width looks to be about 280 (+- 140).

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).

$\endgroup$
  • $\begingroup$ Thank you, but I didn't get it how does the half width equals √N in this case? maybe I'm missing something... $\endgroup$ – aveline de grandpre Jul 20 '18 at 18:21

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.