a) 388178-414000=-25822
b) (388178-414000)/38410000=-0,672‰
c) 15500 - 11900 = 3600
d) 388178+15500-414000-11900=-22222
e) (388178+15500-414000-11900) / 38410000 * 1000 = -0,579‰
f) 38410000/312679 = 122,841