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avehtari / ROS-Examples

Regression and other stories R examples
https://avehtari.github.io/ROS-Examples/
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typo on p. 304 #85

Closed ASKurz closed 3 years ago

ASKurz commented 3 years ago

Toward the bottom of the page, we read:

For our discussion here we shall work with the simple analysis from Section 9.4, comparing the “very attractive” parents in the survey (56% of their children were girls) to the other parents (only 44% of their children were girls). The difference was 8% with a standard error of 3%. (p. 304).

I believe the second percentage should be 48%, not 44%. To work it through, we first load the sexratio.rda data.

load("ROS-Examples-master/SexRatio/data/sexratio.rda")

Now we compute the average percentage among the rows for which x < 2 (i.e., the first four rows).

mean(sexratio$y[1:4])
[1] 47.75

This would have been rounded to 48. Also, when you incorporate the information from the last sentence in the block quote, 56 - 8 = 48.

avehtari commented 3 years ago

Thanks! fixed and added to the errata