In the pension fund model, suppose there is a fourth bond, bond 4. Its unit cost in 2010 is $1020, it returns coupons of $70 in years 2011 to 2014 and a payment of $1070 in 2015. Modify the model to...

In the pension fund model, suppose there is a fourth bond, bond 4. Its unit cost in 2010 is $1020, it returns coupons of $70 in years 2011 to 2014 and a payment of $1070 in 2015. Modify the model to incorporate this extra bond and reoptimize. Does the solution change—that is, should James purchase any of bond 4?