Finding the Fourth Proportional to 139,014.16, 191,949.96 and 128,399.92

Step by Step Solution

1. Step 1: Write the proportion equation
   139,014.16 : 191,949.96 = 128,399.92 : x
2. Step 2: Convert to fraction form
   139,014.16/191,949.96 = 128,399.92/x
3. Step 3: Cross multiply
   139,014.16x = 191,949.96 × 128,399.92
4. Step 4: Simplify right side
   139,014.16x = 24,646,359,508.00
5. Step 5: Solve for x
   x = 24,646,359,508.00/139,014.16
6. Step 6: Final answer
   x = 177,293.88