Finding the Fourth Proportional to 142,390.56, 196,491.12 and 78,724.56

Step by Step Solution

1. Step 1: Write the proportion equation
   142,390.56 : 196,491.12 = 78,724.56 : x
2. Step 2: Convert to fraction form
   142,390.56/196,491.12 = 78,724.56/x
3. Step 3: Cross multiply
   142,390.56x = 196,491.12 × 78,724.56
4. Step 4: Simplify right side
   142,390.56x = 15,468,676,965.91
5. Step 5: Solve for x
   x = 15,468,676,965.91/142,390.56
6. Step 6: Final answer
   x = 108,635.55