Question

Find the constant of proportionality. Then write an equation relating x and y. y is directly proportional to x, and y = 2 when x = 4

Answer 1

y = kx

where:

k= constant of proportionality

y = 2 when x = 4​

Replace:

2 = k4

Solve for k

2/4 = k

k= 1/2

Equation:

y= 1/2 x

constant of proportionality = 1/2