Finding the Fourth Proportional to 128,686.56, 177,592.32 and 72,096

Step by Step Solution

1. Step 1: Write the proportion equation
   128,686.56 : 177,592.32 = 72,096 : x
2. Step 2: Convert to fraction form
   128,686.56/177,592.32 = 72,096/x
3. Step 3: Cross multiply
   128,686.56x = 177,592.32 × 72,096
4. Step 4: Simplify right side
   128,686.56x = 12,803,695,902.72
5. Step 5: Solve for x
   x = 12,803,695,902.72/128,686.56
6. Step 6: Final answer
   x = 99,495.21