Finding the Fourth Proportional to 142,358.72, 196,440 and 78,686.24

Step by Step Solution

1. Step 1: Write the proportion equation
   142,358.72 : 196,440 = 78,686.24 : x
2. Step 2: Convert to fraction form
   142,358.72/196,440 = 78,686.24/x
3. Step 3: Cross multiply
   142,358.72x = 196,440 × 78,686.24
4. Step 4: Simplify right side
   142,358.72x = 15,457,124,985.60
5. Step 5: Solve for x
   x = 15,457,124,985.60/142,358.72
6. Step 6: Final answer
   x = 108,578.70