Finding the Fourth Proportional to 139,817.92, 209,560.38 and 80,530.78

Step by Step Solution

1. Step 1: Write the proportion equation
   139,817.92 : 209,560.38 = 80,530.78 : x
2. Step 2: Convert to fraction form
   139,817.92/209,560.38 = 80,530.78/x
3. Step 3: Cross multiply
   139,817.92x = 209,560.38 × 80,530.78
4. Step 4: Simplify right side
   139,817.92x = 16,876,060,858.50
5. Step 5: Solve for x
   x = 16,876,060,858.50/139,817.92
6. Step 6: Final answer
   x = 120,700.27