Finding the Fourth Proportional to 128,517.92, 177,456.72 and 85,538.72

Step by Step Solution

1. Step 1: Write the proportion equation
   128,517.92 : 177,456.72 = 85,538.72 : x
2. Step 2: Convert to fraction form
   128,517.92/177,456.72 = 85,538.72/x
3. Step 3: Cross multiply
   128,517.92x = 177,456.72 × 85,538.72
4. Step 4: Simplify right side
   128,517.92x = 15,179,420,684.20
5. Step 5: Solve for x
   x = 15,179,420,684.20/128,517.92
6. Step 6: Final answer
   x = 118,111.32