The area ratio is 1:16 meaning that the old area is 1 while the new area is 16. So this is another way of saying "the area is multiplied by 16"
Take the square root of each part of the ratio of 1:16 and we get 1:4
So this is the scale factor. It tells us how the linear components of the circles relate to one another. If the circumference of the smaller circle is 1,then the larger circle has a circumference of 4.
Therefore, the circumference has been multiplied by 4
Answer: 
Step-by-step explanation:

The length of the leg is 5
Answer:
the table does represent a propor. rela. since y=12x
you can multiply the x values by 12 and that y value will be just that, and in this case, all of them are multiplied by 12.
The answer to the question is 1