Finding the Fourth Proportional to 390,061.30, 584,107.80 and 311,329.30

Step by Step Solution

1. Step 1: Write the proportion equation
   390,061.30 : 584,107.80 = 311,329.30 : x
2. Step 2: Convert to fraction form
   390,061.30/584,107.80 = 311,329.30/x
3. Step 3: Cross multiply
   390,061.30x = 584,107.80 × 311,329.30
4. Step 4: Simplify right side
   390,061.30x = 181,849,872,498.54
5. Step 5: Solve for x
   x = 181,849,872,498.54/390,061.30
6. Step 6: Final answer
   x = 466,208.45