Finding the Fourth Proportional to 611,155.40, 917,061.15 and 256,205.30

Step by Step Solution

1. Step 1: Write the proportion equation
   611,155.40 : 917,061.15 = 256,205.30 : x
2. Step 2: Convert to fraction form
   611,155.40/917,061.15 = 256,205.30/x
3. Step 3: Cross multiply
   611,155.40x = 917,061.15 × 256,205.30
4. Step 4: Simplify right side
   611,155.40x = 234,955,927,054.10
5. Step 5: Solve for x
   x = 234,955,927,054.10/611,155.40
6. Step 6: Final answer
   x = 384,445.47