Finding the Fourth Proportional to 128,923.56, 177,917.58 and 72,339.12

Step by Step Solution

1. Step 1: Write the proportion equation
   128,923.56 : 177,917.58 = 72,339.12 : x
2. Step 2: Convert to fraction form
   128,923.56/177,917.58 = 72,339.12/x
3. Step 3: Cross multiply
   128,923.56x = 177,917.58 × 72,339.12
4. Step 4: Simplify right side
   128,923.56x = 12,870,401,169.73
5. Step 5: Solve for x
   x = 12,870,401,169.73/128,923.56
6. Step 6: Final answer
   x = 99,829.71