Finding the Fourth Proportional to 2,139,439.10, 3,209,134.28 and 520,217.10

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139,439.10 : 3,209,134.28 = 520,217.10 : x
2. Step 2: Convert to fraction form
   2,139,439.10/3,209,134.28 = 520,217.10/x
3. Step 3: Cross multiply
   2,139,439.10x = 3,209,134.28 × 520,217.10
4. Step 4: Simplify right side
   2,139,439.10x = 1,669,446,526,051.10
5. Step 5: Solve for x
   x = 1,669,446,526,051.10/2,139,439.10
6. Step 6: Final answer
   x = 780,319.72