Here's how to calculate the time it takes for the radio signal to travel from Mars to Earth:

1. Convert distance to meters:

* 7.03 x 10^7 km * (1000 m/km) = 7.03 x 10^10 m

2. Use the formula: time = distance / speed

* time = (7.03 x 10^10 m) / (3.00 x 10^8 m/s)

* time ≈ 234.33 seconds

Therefore, it takes approximately 234.33 seconds for the radio signal to travel from Mars to Earth.