Finding the Fourth Proportional to 139,061.60, 208,543.80 and 72,479.60

Step by Step Solution

1. Step 1: Write the proportion equation
   139,061.60 : 208,543.80 = 72,479.60 : x
2. Step 2: Convert to fraction form
   139,061.60/208,543.80 = 72,479.60/x
3. Step 3: Cross multiply
   139,061.60x = 208,543.80 × 72,479.60
4. Step 4: Simplify right side
   139,061.60x = 15,115,171,206.48
5. Step 5: Solve for x
   x = 15,115,171,206.48/139,061.60
6. Step 6: Final answer
   x = 108,694.07