Finding the Fourth Proportional to 386,404.89, 578,875.74 and 257,933.82

Step by Step Solution

1. Step 1: Write the proportion equation
   386,404.89 : 578,875.74 = 257,933.82 : x
2. Step 2: Convert to fraction form
   386,404.89/578,875.74 = 257,933.82/x
3. Step 3: Cross multiply
   386,404.89x = 578,875.74 × 257,933.82
4. Step 4: Simplify right side
   386,404.89x = 149,311,630,923.53
5. Step 5: Solve for x
   x = 149,311,630,923.53/386,404.89
6. Step 6: Final answer
   x = 386,412.37