Objects 1 and 2 attract each other with a gravitational force of 72.0 units. If the distance separating Objects 1 and 2 is
changed to four times the original value (i. e., quadrupled),
then the new gravitational force will be units.

The new gravitational force will be of 4.5 units

Explanation:

Recall that the formula for the gravitational force between two objects of masses m1 and m2 separated by a distance d is given by:

in our case, we are told that such gives 72 units of force:

Then we change the distance between the objects to 4 times the original (4 * d), such will produce a new gravitational force Fg':

Therefore the new gravitational force would be of 4.5 units