Answer:
Difference = 6 inches 
Explanation:
Given information,
→ Meg measured the length of some pieces of the wire.
Now we have to,
→ find the difference between the longest and shortest piece of wire. 
Then the difference will be,
→ Longest wire - Shortest wire 
→ 9 - 3 
→ 6 inches
Hence, the difference is 6 inches.