"Excercise Rate" in Swaptions (#63, page 287, Example 7)

Exercise rate given in Example 7 is 4%. The problem doesn’t gross this up to an annual rate – it treats 4% as the payment rate at each 180 day interval. The problems in the EOC treat the exercise rate as an annual rate. (Look at problems 9 and 10 on pages 300-301). What am I missing here? I cannot figure out why the example is different from the EOCs.

Have noticed this - I guess the one in the example meant 4% per 6 months - in general, however, rates should be quoted on annual basis

Interestingly, the text also specifies a rate per payment rather than a rate per year.