Answer : Calculation of Value at the end of 15 years :

Calculation of Future value of Annuity

Future Value of Annuity = Periodic Payment * {[(1+ r)^n - 1 ] / r }

where

rate of interest per period is 6.1% or 0.061 / 2 = 0.0305(Divided by 2 as compounded semiannually)

n is the number of periods i.e 15 * 2 = 30 (Multiplied by 2 as compounded semiannually)

Periodic payment is 17773

Future Value of Annuity = 17773 * {[(1+ 0.0305)^30 - 1 ] / 0.0305 }

= 17773 * { 1.462860897 / 0.0305}

= 17773 * 47.96265236

= 852440.22