What expression represents the decimal 72.603?

7 x 10 + 2 x 1 + 6 x 1/100 + 3 x 1/1000
7 x 1 + 2 x 10 + 6 x 1/10 + 3 x 1/100
7 x 10 + 2 x 1 + 6 x 1/10+ 3 x 1/1000
7 x 1 + 2 x 1 + 6 x 1/10+ 3 x 1/100