(4) Suppose a (t)--u2+t+y. If $100 invested at time 0 accumulates to $152 at time 4 and $200 invested at time 0 accumulates to $240 at time 2, find the ted value at time 8 of $1,600 invested at time 6. [HINT: First find the X that you would need unknowns and . Then determine how much money to deposit at time 0 in order to have an accumulation of $1,600 at time 6. The desired answer is the accumulated value of X at time 8.]