The formula for the volume of a cone is given by the following equation:
V = 1/3 * π * r2 * h
where V is the volume of the cone, r is the radius of the cone, and h is the height of the cone.
In this case, we are given that the radius of the cone is 2.5 units and the volume of the cone is 19 cubic units. We can use this information to complete the expression that represents the height of the cone as follows:
V = 1/3 * π * r2 * h
19 cubic units = 1/3 * π * 2.5 units2 * h
19 cubic units = 1/3 * π * 6.25 units2 * h
19 cubic units = 1/3 * 19.63 units2 * h
19 cubic units = 6.54 units2 * h
h = 19 cubic units / 6.54 units2
h = 2.9 cubic units / 6.54 units
Therefore, the expression that represents the height of the cone is 2.9 cubic units / 6.54 units.