Finding the Third Proportional to 8,557.31 and 12,722.06

Step by Step Solution

1. Step 1: Write the proportion equation
   8,557.31 : 12,722.06 = 12,722.06 : x
2. Step 2: Convert to fraction form
   8,557.31/12,722.06 = 12,722.06/x
3. Step 3: Cross multiply
   8,557.31x = 12,722.06 × 12,722.06
4. Step 4: Simplify right side
   8,557.31x = 161,850,874.25
5. Step 5: Solve for x
   x = 161,850,874.25/8,557.31
6. Step 6: Final answer
   x = 18,913.75