Finding the Third Proportional to 12,124.50 and 18,139.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,124.50 : 18,139.50 = 18,139.50 : x
2. Step 2: Convert to fraction form
   12,124.50/18,139.50 = 18,139.50/x
3. Step 3: Cross multiply
   12,124.50x = 18,139.50 × 18,139.50
4. Step 4: Simplify right side
   12,124.50x = 329,041,460.25
5. Step 5: Solve for x
   x = 329,041,460.25/12,124.50
6. Step 6: Final answer
   x = 27,138.56