This is the difference between the current value of the bond portfolio and the present value of the estimated terminal value given the current return:
Current value of the portfolio = $3.024 million as determined in the previous question.
Assets required given a terminal value of $3,600,000 and current rates of return of 6.5%:
3,600,000 / (1.0325)8 = 2,787,289
Dollar safety margin = 3,023,906 - 2,787,289 = 236,617
