Finding the Fourth Proportional to 142,403.02, 196,487.72 and 78,728.50

Step by Step Solution

1. Step 1: Write the proportion equation
   142,403.02 : 196,487.72 = 78,728.50 : x
2. Step 2: Convert to fraction form
   142,403.02/196,487.72 = 78,728.50/x
3. Step 3: Cross multiply
   142,403.02x = 196,487.72 × 78,728.50
4. Step 4: Simplify right side
   142,403.02x = 15,469,183,464.02
5. Step 5: Solve for x
   x = 15,469,183,464.02/142,403.02
6. Step 6: Final answer
   x = 108,629.60