Finding the Fourth Proportional to 139,563.60, 209,442.60 and 89,764.80

Step by Step Solution

1. Step 1: Write the proportion equation
   139,563.60 : 209,442.60 = 89,764.80 : x
2. Step 2: Convert to fraction form
   139,563.60/209,442.60 = 89,764.80/x
3. Step 3: Cross multiply
   139,563.60x = 209,442.60 × 89,764.80
4. Step 4: Simplify right side
   139,563.60x = 18,800,573,100.48
5. Step 5: Solve for x
   x = 18,800,573,100.48/139,563.60
6. Step 6: Final answer
   x = 134,709.72