Suppose a species of sea turtles is confined to an island and has a current population of 70 turtles. If the population, N, is modeled by N=70(5+2t)/(5+.04t) , t≥0 where t is the time in years, how many turtles are predicated to be on the island in 38 years?

ok well i thought this was pretty simple, but it seemed that i was wrong. i plugged 38 into the formula like so N=70(5+2(38)/(5+.04(38) and got 1520.4 which did not match the answer in the back of the book. what did i do wrong???