Company B; the ratios of cost to weight are equivalent.
Step-by-step explanation:
Step 1:
In the equation,
k is the constant of proportionality.
If the values are in accordance with
, the values of k will be constant for all the values.
So we determine the values of k for both the companies and see which has a constant k.
If
. In these tables, y is the total cost and x is the weight in lbs.
Step 2:
For company A,
when 
when 
when 
For company B,
when 
when 
when 
So company B has a constant value of
.