Finding the Third Proportional to 2,172 and 5,355

Step by Step Solution

1. Step 1: Write the proportion equation
   2,172 : 5,355 = 5,355 : x
2. Step 2: Convert to fraction form
   2,172/5,355 = 5,355/x
3. Step 3: Cross multiply
   2,172x = 5,355 × 5,355
4. Step 4: Simplify right side
   2,172x = 28,676,025
5. Step 5: Solve for x
   x = 28,676,025/2,172
6. Step 6: Final answer
   x = 13,202.59