Finding the Fourth Proportional to 429,404.10, 644,106.15 and 429,404.10

Step by Step Solution

1. Step 1: Write the proportion equation
   429,404.10 : 644,106.15 = 429,404.10 : x
2. Step 2: Convert to fraction form
   429,404.10/644,106.15 = 429,404.10/x
3. Step 3: Cross multiply
   429,404.10x = 644,106.15 × 429,404.10
4. Step 4: Simplify right side
   429,404.10x = 276,581,821,645.22
5. Step 5: Solve for x
   x = 276,581,821,645.22/429,404.10
6. Step 6: Final answer
   x = 644,106.15