Answer:
The cost difference between lowest and highest bid $ 251.20
Explanation:
Given,
The average quote for the traffic control subcontractor = $ 1570,
Also, the lowest bid is 4 % under average,
That is, lowest bid = average quote - 4% average quote
= 1570 - 4% of 1570




While, the highest bid is 12% above average,
That is, the highest bid = average quote + 12% average quote
= 1570 + 12% of 1570




Hence, the cost difference between lowest and highest bid = $ 1758.4 - $ 1507.2 = $ 251.20