Finding the Fourth Proportional to 128,641.72, 177,533.76 and 72,056.56

Step by Step Solution

1. Step 1: Write the proportion equation
   128,641.72 : 177,533.76 = 72,056.56 : x
2. Step 2: Convert to fraction form
   128,641.72/177,533.76 = 72,056.56/x
3. Step 3: Cross multiply
   128,641.72x = 177,533.76 × 72,056.56
4. Step 4: Simplify right side
   128,641.72x = 12,792,472,029.47
5. Step 5: Solve for x
   x = 12,792,472,029.47/128,641.72
6. Step 6: Final answer
   x = 99,442.64