Finding the Fourth Proportional to 129,516.69, 178,738.56 and 72,155.98

Step by Step Solution

1. Step 1: Write the proportion equation
   129,516.69 : 178,738.56 = 72,155.98 : x
2. Step 2: Convert to fraction form
   129,516.69/178,738.56 = 72,155.98/x
3. Step 3: Cross multiply
   129,516.69x = 178,738.56 × 72,155.98
4. Step 4: Simplify right side
   129,516.69x = 12,897,055,599.81
5. Step 5: Solve for x
   x = 12,897,055,599.81/129,516.69
6. Step 6: Final answer
   x = 99,578.33