Circle T is dilated to create circle T'. The radius of circle T is 4 units, while the diameter of circle T' is 10 units.
Find the scale factor used to dilate circle T to circle T'.
The scale factor is found by dividing the diameter of the dilated circle by the diameter of the original circle.
The diameter of circle T is 4 units, so the diameter of circle T' is 10 units.
Therefore, the scale factor is 10 / 4 = <<10/4=2.5>>2.5.
So, circle T was dilated by a scale factor of 2.5 to create circle T'.