Finding the Fourth Proportional to 387,431.89, 534,801.04 and 290,914.56

Step by Step Solution

1. Step 1: Write the proportion equation
   387,431.89 : 534,801.04 = 290,914.56 : x
2. Step 2: Convert to fraction form
   387,431.89/534,801.04 = 290,914.56/x
3. Step 3: Cross multiply
   387,431.89x = 534,801.04 × 290,914.56
4. Step 4: Simplify right side
   387,431.89x = 155,581,408,511.86
5. Step 5: Solve for x
   x = 155,581,408,511.86/387,431.89
6. Step 6: Final answer
   x = 401,570.99