Finding the Fourth Proportional to 142,321.80, 196,402.20 and 78,660.72

Step by Step Solution

1. Step 1: Write the proportion equation
   142,321.80 : 196,402.20 = 78,660.72 : x
2. Step 2: Convert to fraction form
   142,321.80/196,402.20 = 78,660.72/x
3. Step 3: Cross multiply
   142,321.80x = 196,402.20 × 78,660.72
4. Step 4: Simplify right side
   142,321.80x = 15,449,138,461.58
5. Step 5: Solve for x
   x = 15,449,138,461.58/142,321.80
6. Step 6: Final answer
   x = 108,550.75