Finding the Fourth Proportional to 129,019.47, 178,040.81 and 71,662.51

Step by Step Solution

1. Step 1: Write the proportion equation
   129,019.47 : 178,040.81 = 71,662.51 : x
2. Step 2: Convert to fraction form
   129,019.47/178,040.81 = 71,662.51/x
3. Step 3: Cross multiply
   129,019.47x = 178,040.81 × 71,662.51
4. Step 4: Simplify right side
   129,019.47x = 12,758,850,078.52
5. Step 5: Solve for x
   x = 12,758,850,078.52/129,019.47
6. Step 6: Final answer
   x = 98,890.89