Answer
The minimum radius is 69 meters.
Work Step by Step
At the minimum radius, the normal force from the road on the car will be 0. Then $F_g$ will provide the centripetal force on the car:
$v = (95 ~km/h)(\frac{1 ~h}{3600 ~s})(\frac{1000 ~m}{1 ~km})$
$v = 26 ~m/s$
We can use the velocity to find the minimum radius:
$mg = m \frac{v^2}{r}$
$r = \frac{v^2}{g}$
$r = \frac{(26 ~m/s)^2}{(9.8 ~m/s^2)}$
$r = 69~m$
The minimum radius is 69 meters.