Submitted by coeurveineux on Tue, 04/17/2018 - 09:38

Hello,

Just to report a minor typo in STEP II Statistics topic notes : The Poisson distribution (page 2) defines P( X = r ) = f(n) instead of f(r)

Hope this helps !

Submitted by coeurveineux on Tue, 04/17/2018 - 09:38

Forums:

Hello,

Just to report a minor typo in STEP II Statistics topic notes : The Poisson distribution (page 2) defines P( X = r ) = f(n) instead of f(r)

Hope this helps !

## Thanks!

Corrected now. Thanks for pointing it out!

## You're welcome !

Well, you're welcome ! Another typo in STEP II Miscellaneous may be the equation of the circle of radius R passing through $(a,b)$. I may be mistaken, but if the circle (eg the curved line) passes through $(a,b)$, we can't have the equation as there are an infinite number of circle of radius R passing through (a,b). In the equation given, $(a,b)$ is the centre.

Also, something I'm not quite sure about is the expansion of $(1 + x)^k$. We don't need $abs(x) < 1$, do we ? The latter condition is only required if we want to approximate $(1 + x)^k$ by the first terms of the expansion.

## Edit

Well, in fact, now I've understood the meaning of the binomial expansion. Sorry !

However, in the correction of STEP II miscellaneous Q7 (2007 S2 Q1), there is one too many $4$ in the approximation of $\sqrt{6}$ : $\sqrt{6} \approx 2.44949$ and not $\sqrt{6} \approx 2.444949$.

Anyway, thank you for being so helpful, and hope this helps.

## Thanks

Yep, agreed!

## Which question?

For the typo about a circle, I am assuming that this is from the solutions document? If so, which question is it please? (I have had a quick scan through and cannot find it!).

Thanks for all the help :-)

## Link

Oops, sorry I forgot to mention it was in the topic notes (here)

## Thanks

That was an odd mistake to make, sorry!

## Mistakes corrected

Thanks again!