Finding the Fourth Proportional to 129,256.51, 178,390.61 and 72,678.82

Step by Step Solution

1. Step 1: Write the proportion equation
   129,256.51 : 178,390.61 = 72,678.82 : x
2. Step 2: Convert to fraction form
   129,256.51/178,390.61 = 72,678.82/x
3. Step 3: Cross multiply
   129,256.51x = 178,390.61 × 72,678.82
4. Step 4: Simplify right side
   129,256.51x = 12,965,219,033.88
5. Step 5: Solve for x
   x = 12,965,219,033.88/129,256.51
6. Step 6: Final answer
   x = 100,306.12