Finding the Third Proportional to 13,139.50 and 20,401.50

Step by Step Solution

1. Step 1: Write the proportion equation
   13,139.50 : 20,401.50 = 20,401.50 : x
2. Step 2: Convert to fraction form
   13,139.50/20,401.50 = 20,401.50/x
3. Step 3: Cross multiply
   13,139.50x = 20,401.50 × 20,401.50
4. Step 4: Simplify right side
   13,139.50x = 416,221,202.25
5. Step 5: Solve for x
   x = 416,221,202.25/13,139.50
6. Step 6: Final answer
   x = 31,677.10