Finding the Fourth Proportional to 128,944.89, 177,946.35 and 72,355.05

Step by Step Solution

1. Step 1: Write the proportion equation
   128,944.89 : 177,946.35 = 72,355.05 : x
2. Step 2: Convert to fraction form
   128,944.89/177,946.35 = 72,355.05/x
3. Step 3: Cross multiply
   128,944.89x = 177,946.35 × 72,355.05
4. Step 4: Simplify right side
   128,944.89x = 12,875,317,051.57
5. Step 5: Solve for x
   x = 12,875,317,051.57/128,944.89
6. Step 6: Final answer
   x = 99,851.32