Final answer:
The fine for a first conviction of the child restraint law varies by location, and the correct answer would depend on local laws. For the exact fine, consult the local traffic laws or motor vehicle department.
Step-by-step explanation:
The cost of the first conviction for violating the child restraint law can vary depending on the state or country's regulations. Without specific jurisdictional information, it is challenging to provide the exact amount for such a violation. Generally, laws surrounding child restraint systems are set to ensure the safety of young passengers in vehicles. Fines are often put in place to incentivize proper usage of car seats and seat belts designed for children. To determine the precise penalty for a first-time offense, one would need to consult the local traffic laws or the department of motor vehicles for the region in question.