Use the Gauss-Seidel iterative process to find the solution of the following system of equations, take the initial solution as (1, 1, 1). 

(Do four iterations only). 

1.2x + 4.4y − 1.9z = −4.2 

5.1x − 1.3y + 2.4z = 2.7 

−2.6x + 1.7y − 6.3z = 9.6