Hi,
First of all really enjoying the book! Still working my way through it but I have spotted a few errors so far:
Page 44: I think the third formula should be a probability rather than a score (this concept hasn't been introduced yet), and is missing the divisor P(containts driving & cant & txt).
Page 45: Top formula should not have logarithms applied
Page 63: "another jump up, from 96.7% to 98.3" should read "another jump up, from 97.9% to 98.3%"