Finding the Fourth Proportional to 129,698.72, 178,953.76 and 78,710.31

Step by Step Solution

1. Step 1: Write the proportion equation
   129,698.72 : 178,953.76 = 78,710.31 : x
2. Step 2: Convert to fraction form
   129,698.72/178,953.76 = 78,710.31/x
3. Step 3: Cross multiply
   129,698.72x = 178,953.76 × 78,710.31
4. Step 4: Simplify right side
   129,698.72x = 14,085,505,925.27
5. Step 5: Solve for x
   x = 14,085,505,925.27/129,698.72
6. Step 6: Final answer
   x = 108,601.73