Samuel's Car Service will charge a flat travel fee of $4.75 for anyone making a trip. They charge an additional set rate of $1.50 per mile that is traveled. What is an equation that represents the charges?

1) y=1.5x+1.5
2) y=4.75x+4.75
3) y=1.5x+4.75
4) y=4.75x+1.5