To find the scale factor of the dilation, we can compare the corresponding dimensions of the original and the enlarged card.
The original card has a length of 3 1/2 inches and is being enlarged to a length of 5 1/4 inches. So the scale factor for the length is:
5 1/4 inches / 3 1/2 inches = 3/2
Similarly, the original card has a width of 2 inches and is being enlarged to a width of 3 inches. So the scale factor for the width is:
3 inches / 2 inches = 3/2
Therefore, the scale factor of the dilation is 3/2 or 1.5.