If it is simple interest, then

19% of $1599 is 0.19 times $1599, or $303.81

After one year, you have to pay $303.81 more than the $1599.

After one year, it will cost you $1599 +$303.81 = $1902.81

Usually, it is computed like this:

After one year, cost = (1.19)($1599) = $1902.81