Multiple the number of pounds by ___ to find total cost

Answer:
4
Step-by-step explanation:
The function is 4x.
For every pound you have, you will have 4 times that amount in total cost. This is because of the pattern being shown. Example: 3 × 4 = 12 6 × 4 = 24 9 × 4 = 36.. and it just goes on and on.