Final answer:
The cost when 125 parts are produced is $62,700.
Step-by-step explanation:
To find the cost when 125 parts are produced, we can substitute n = 125 into the given equation:
c = 500(125) + 200
c = 62,500 + 200
c = 62,700
Therefore, the cost when 125 parts are produced is $62,700.