If stopping distance is proportional to the square of the velocity then we know that where k is some constant. So find k from the 177 ft and 70 mph data, then use that constant to calculate the distance for the other two speeds.

For example,

(Check the units here. We are requiring that the distance is in feet and the speed is in mph in order to use this constant!)

So the stopping distance for 45 mph is

-Dan