Question

The following set of ordered pairs is an example of direct variation, find the constant ratio between the variables. (Hint: Find k.)

(2, 4) (5, 10) (7, 14) (11, 22)
A. k=2
B. k=8
C. k=-2
D. k= 1/2

Answer 1

Direct variation looks like
y=kx, so

k=y/x

(2, 4) k=4/2=2
(5, 10) k=10/5=2
(7, 14) k=14/7=2
(11, 22) k=22/11=2

Answer:A.k=2.