I've got this book right in front of me! OMG! I never noticed that there are no yardage numbers given ANYWHERE in the book, not even on page 140...which is just a description of the type of yarn...no yardages given whatsoever.
Predicting yardage requirements is tricky business. All she prolly knows is how much yarn she used for her model sweater, which if prolly the only one that exists on the planet!
But regardless...I think she should have given the yardage used for the model sweaters she is wearing in the book.
Now that I know this about the book, I regard this book as useless.
Not everyone has an endless supply of yarn in a closet.
However, that said...if you look into other cardigan designs that use super-duper bulky yarn (1.9 st per inch)...and see what yardages are stated, you will come pretty close to how much you need.
I wish I had not purchased this book. I understand how frustrated you must feel.