2012 schweser book 5 page 72 return calculation

When dealing with the Millie’s case and calculating for required return.

here is what is written in the book:

FV: -college expense

PMT: - travel expenses

PV: 1,000,000


CPT I/Y = before tax return

My concern is that the I/Y being calculated should be after tax required rate of return, should it not?

Then we would back out the before tax required return with 1-T.

Please confirm