Finding the Third Proportional to 12,978,873 and 20,359,269

Step by Step Solution

1. Step 1: Write the proportion equation
   12,978,873 : 20,359,269 = 20,359,269 : x
2. Step 2: Convert to fraction form
   12,978,873/20,359,269 = 20,359,269/x
3. Step 3: Cross multiply
   12,978,873x = 20,359,269 × 20,359,269
4. Step 4: Simplify right side
   12,978,873x = 414,499,834,214,361
5. Step 5: Solve for x
   x = 414,499,834,214,361/12,978,873
6. Step 6: Final answer
   x = 31,936,504.36