Transform the following linear programming model into standard form and solve by using the computer:
Maximize Z = 140x1 + 205x2 + 190x3
Subject to
10x1 + 15x2 + 8x3 ≤ 610
x1 / x2 ≤ 3
x1 ≥ 0.4(x1 + x2 + x3)
x2 ≥ x3
x1, x2, x3 ≥ 0