Finding the Fourth Proportional to 442,003.42, 609,804.72 and 289,128.88

Step by Step Solution

1. Step 1: Write the proportion equation
   442,003.42 : 609,804.72 = 289,128.88 : x
2. Step 2: Convert to fraction form
   442,003.42/609,804.72 = 289,128.88/x
3. Step 3: Cross multiply
   442,003.42x = 609,804.72 × 289,128.88
4. Step 4: Simplify right side
   442,003.42x = 176,312,155,712.31
5. Step 5: Solve for x
   x = 176,312,155,712.31/442,003.42
6. Step 6: Final answer
   x = 398,893.19