Finding the Fourth Proportional to 129,196.72, 178,295.52 and 78,218.80

Step by Step Solution

1. Step 1: Write the proportion equation
   129,196.72 : 178,295.52 = 78,218.80 : x
2. Step 2: Convert to fraction form
   129,196.72/178,295.52 = 78,218.80/x
3. Step 3: Cross multiply
   129,196.72x = 178,295.52 × 78,218.80
4. Step 4: Simplify right side
   129,196.72x = 13,946,061,619.78
5. Step 5: Solve for x
   x = 13,946,061,619.78/129,196.72
6. Step 6: Final answer
   x = 107,944.39