Finding the Fourth Proportional to 128,669.76, 177,564.15 and 72,081.54

Step by Step Solution

1. Step 1: Write the proportion equation
   128,669.76 : 177,564.15 = 72,081.54 : x
2. Step 2: Convert to fraction form
   128,669.76/177,564.15 = 72,081.54/x
3. Step 3: Cross multiply
   128,669.76x = 177,564.15 × 72,081.54
4. Step 4: Simplify right side
   128,669.76x = 12,799,097,380.79
5. Step 5: Solve for x
   x = 12,799,097,380.79/128,669.76
6. Step 6: Final answer
   x = 99,472.46