it is from the book Construction Productivity: measurent & improvement by James Adrian

6. Based on data below, calculate gross profit margin and job estimating risk and comment whether the productivity has been improved or not from job 1 to job 5? Job Number Contact Amount (S) 150.000 180.000 120,000 200,000 170.000 Estimated Cost (S) 102.000 127.500 76.500 144.300 119.000 Actual Cost 130.000 130.000 75.000 120.000 158,000