Finding the Fourth Proportional to 156,978.80, 235,122.60 and 139,468.40

Step by Step Solution

1. Step 1: Write the proportion equation
   156,978.80 : 235,122.60 = 139,468.40 : x
2. Step 2: Convert to fraction form
   156,978.80/235,122.60 = 139,468.40/x
3. Step 3: Cross multiply
   156,978.80x = 235,122.60 × 139,468.40
4. Step 4: Simplify right side
   156,978.80x = 32,792,172,825.84
5. Step 5: Solve for x
   x = 32,792,172,825.84/156,978.80
6. Step 6: Final answer
   x = 208,895.55