Trapezoid W′X′Y′Z′ is the image of trapezoid WXYZ under a dilation through point C. What scale factor was used in the dilation?

The correct answer is:
7/3
Explanation:
The image, W'X'Y'Z', is larger than the pre-image WXYZ. The new side given to us is 14, compared to the old side of 6; this gives us the ratio
14/6
This can be simplified by dividing top and bottom by 2:
(14÷2)/(6÷2) = 7/3
This is the scale factor.