Kaela traced 4 circles, each with a different diameter, on a piece of paper. For each circle, she laid a piece of string along the outline and then measured the length of the string. Her results are shown in the table below. 2 in 6.28 in
5 in 15.70 in
8 in 25.12 in
11 in 34.54 in
Kaela wrote an equation, y = kx, to model the relationship between the circumference, y, and the diameter, x, of the circle. Which of the following statements correctly describe what k represents in this equation?
k represents the unit rate
k represents the radius
k represents the constant of proportionality
k represents the area
A.
I, II, and IV only
B.
I and IV only
C.
I and III only
D.
II and III only