Finding the Fourth Proportional to 129,056.40, 178,162.56 and 80,685.18

Step by Step Solution

1. Step 1: Write the proportion equation
   129,056.40 : 178,162.56 = 80,685.18 : x
2. Step 2: Convert to fraction form
   129,056.40/178,162.56 = 80,685.18/x
3. Step 3: Cross multiply
   129,056.40x = 178,162.56 × 80,685.18
4. Step 4: Simplify right side
   129,056.40x = 14,375,078,222.86
5. Step 5: Solve for x
   x = 14,375,078,222.86/129,056.40
6. Step 6: Final answer
   x = 111,386.02