By Kepler`s 3rd Law:
The square of the orbital period of a planet is directly proportional to a cube of semi-major axis of its orbit:
T² = R³
T = 1.88
1.88² = R³
3.5344 = R³
R = ∛ 3.5344 = 1.524 A U
1 Astronomic Unit = 149,600,000 km ( or the distance: Earth to the Sun )
1.524 * 149,600,600 = 227,990,400 km
The average distance from Mars to the Sun is 227,990,400 km.