Finding the Fourth Proportional to 1,219,081.31, 1,828,742.24 and 420,257.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,219,081.31 : 1,828,742.24 = 420,257.69 : x
2. Step 2: Convert to fraction form
   1,219,081.31/1,828,742.24 = 420,257.69/x
3. Step 3: Cross multiply
   1,219,081.31x = 1,828,742.24 × 420,257.69
4. Step 4: Simplify right side
   1,219,081.31x = 768,542,989,387.83
5. Step 5: Solve for x
   x = 768,542,989,387.83/1,219,081.31
6. Step 6: Final answer
   x = 630,428.00