Finding the Third Proportional to 2,420 and 5,280

Step by Step Solution

1. Step 1: Write the proportion equation
   2,420 : 5,280 = 5,280 : x
2. Step 2: Convert to fraction form
   2,420/5,280 = 5,280/x
3. Step 3: Cross multiply
   2,420x = 5,280 × 5,280
4. Step 4: Simplify right side
   2,420x = 27,878,400
5. Step 5: Solve for x
   x = 27,878,400/2,420
6. Step 6: Final answer
   x = 11,520