Answer:
0.78
Step-by-step explanation:
The constant of proportionality is the "k" in y = kx.
y is the dependent variable (whatever you do to x changes y)
x is the independent variable (it doesn't change in relation to y)
Your pounds of apples is your x
Your cost is your y
From the first row: 0.78 = (k)(1), which simplifies to k = 0.78
If you want to test it out, pick another line:
y = kx
3.12 = (k)(4)
divide both sides by 4
k = 0.78
It's great when tables like this have something in the x column that is a 1...because then the y is also the k
