Finding the Fourth Proportional to 129,018.47, 178,039.43 and 71,661.51

Step by Step Solution

1. Step 1: Write the proportion equation
   129,018.47 : 178,039.43 = 71,661.51 : x
2. Step 2: Convert to fraction form
   129,018.47/178,039.43 = 71,661.51/x
3. Step 3: Cross multiply
   129,018.47x = 178,039.43 × 71,661.51
4. Step 4: Simplify right side
   129,018.47x = 12,758,573,144.83
5. Step 5: Solve for x
   x = 12,758,573,144.83/129,018.47
6. Step 6: Final answer
   x = 98,889.51