Version 
Location 
Description 
Submitted By 
Date Submitted 
Date Corrected 
Printed, PDF, Safari Books Online, Other Digital Version 
Page 4
Exercise 12, bullet point 3 
URL has changed.
Was: http://nsfg.icpsr.umich.edu/cocoon/WebDocs/NSFG/public/index.htm
Now: http://www.icpsr.umich.edu/nsfg6/
Thanks to Jeff Pickhardt for letting me know.

Allen B. Downey 
Feb 14, 2012 
May 15, 2012 
Other Digital Version 
13
1st paragraph 
Original sentence: "... a formula for variance with n 1 in the denominator, rather than n. This statistic is called the “sample variance,” and it is used to estimate the variance in a population using a sample. We will come back to this in Chapter 8."
"sample variance" should be "unbiased variance"
Note from the Author or Editor: Change this sentence to
"This statistic is used to estimate the variance in a population using a sample."

Hidetosi Sirai 
Jan 27, 2014 

Other Digital Version 
23
Ch2 Sec on 'Variance' last paragraph of Sec. 
This is in the ePub, which I'm reading on my iPad:
"This statistic is called the “sample variance,” and it is used to estimate the variance in a population using a sample. We will come back to this in Chapter ."
That's right. Chapter... what? No number or reference. In the PDF the quote is:
"This statistic is called the “sample variance,” and it is used to estimate the variance in a population using a sample. We will come back to this in Chapter 8."
Please fix this in the ePub..
Note from the Author or Editor: I don't have the ePub version, so I can't confirm. Also, these links get autogenerated, so I can't fix it.

Leo Marihart 
Sep 09, 2011 

Printed 
Page 30
last paragraph 
From the referred URL (http://coolrunning.com/results/10/ma/Apr25_27thAn_set1.shtml) there is no division "F2029". The correct division would be "F2039".
Note from the Author or Editor: The submitter is correct. I have made this change and checked in a modified XML file (revision 518192).

Jonathan Palardy 
Jun 09, 2012 

Printed 
Page 35
Figure 4.3 
The scale of the figure is incorrect. Should be log y and linear x.

Allen B. Downey 
Sep 16, 2011 
Sep 21, 2011 
PDF 
Page 37
Last paragraph 
The median of an exponential distribution is given as log(2)/lambda. Shouldn't that be ln(2)/lambda?
Note from the Author or Editor: Yes, that would be clearer. Thanks!

Anonymous 
Jun 28, 2012 

PDF, Other Digital Version 
Page 44

"What conclusion do you draw about the distribution of sizes for cities and towns? You can download a solution from http://populations_cdf.py."
Link should be http://thinkstats.com/populations_cdf.py

Ernie Braganza 
Jul 28, 2011 
Sep 21, 2011 
Printed 
Page 53
3nd display equation 
The formula for the binomial coefficient is incorrect.

Allen B. Downey 
Sep 16, 2011 
Sep 21, 2011 
Printed, PDF, ePub, Mobi, Safari Books Online, Other Digital Version 
Page 63
3rd equation from the bottom 
"dx" of the right edge is missing
Note from the Author or Editor: Looks like this is page 66 of version the paper edition. Third equation from bottom should have dx at the end.

Anonymous 
Sep 10, 2012 

PDF 
Page 68
last equation (last paragraph) 
PDF Version 1.3 :
The minus sign is missing before \lambda(zx)
Note from the Author or Editor: Please add a minus sign () before \lambda
Should be:
\[ \PDF_Z(z) = \infint \PDF_X(x)~\PDF_Y(zx) \spa dx =
\infint \lambda e^{\lambda x}~\lambda e^{\lambda (zx)} dx \]

Christoph Lendenmann 
May 27, 2013 

Printed, PDF, ePub, Mobi, Safari Books Online, Other Digital Version 
Page 83
2nd and 3rd equations 
The symbols of normal distribution N is required before the parentheses.
Note from the Author or Editor: Please make this change.

Anonymous 
Sep 10, 2012 

PDF 
Page 95
bottom 
PDF version 1.3:
Should be a = 2N/(N+1) instead of a = 2N(N1)
Note from the Author or Editor: Please make this change

Christoph Lendenmann 
Jun 01, 2013 

Printed, PDF, ePub, Mobi, Safari Books Online, Other Digital Version 
Page 99
3rd equation's numerator 
\sigma dx_{i}dy_{x} should be \sigma dx_{i}dy_{i}
Note from the Author or Editor: Please make this change

Anonymous 
Sep 10, 2012 

PDF 
Page 101
2nd equation 
PDF version 1.3 :
In the second equation for \rho : the denominator is wrong. It should be \sqrt(\sum dxi^2)*\sqrt(\sum dyi^2).

Christoph Lendenmann 
Jun 01, 2013 
