Determine the constant of proportionality (k) for the table and write the relationship between y and x. (1 point)
x, 9, 4, 2, 11
y, 63, 28, 14, 77
a. k = 1/7
b. k = - 1/7
c. k= -7
d. k = 7
choose one
c. k = -7
The relationship between y and x is y = -7x.