The question is: What is the after tax cost of debt for Ford given its effective tax rate for 2018 was 15%?

I used the following;

Coupon Rate of 4.346%

Tax Rate of 15$

Loan amount of $1,500,000 - I got this from the "Amount Outstanding" on the Bond Details as of 3/19

$1,500,000*.04346 (coupon rate) = $65,190

$65,190*.15 (tax rate) = $9,778.50

$65,190 - $9,778.50 = $55,411.50

$55,411.50 / $1,500,000 = 3.694% is the after tax cost of debt for Ford.

Am I in the ballpark?