How would you explain an number based on a 4% change to the notes payable section?

"Assume that, at the end of 2014, the prevailing market rate for interest obligations similar to these notes was 4.0%.What would be the approximate net carrying or book value of the notes at the year end? Explain."

The Company's Long-Term Debt footnote (not attached) includes the following information:

In the 2013 third quarter, we issued $350 million aggregate principal amount of 3.4 percent Series M Notes due 2020 (the "Series M Notes"). We received net proceeds of approximately $345 million from the offering, after deducting the underwriting discount and estimated expenses. We pay interest on the Series M Notes on April 15 and October 15 of each year, commencing on April 15, 2014.

These Series M Notes are described as:

Series M Notes, interest rate of 3.4%, face amount of $350, maturing October 15, 2020 (effective interest rate of 3.6%)