Finding the Fourth Proportional to 142,398.72, 196,495.20 and 78,726.24

Step by Step Solution

1. Step 1: Write the proportion equation
   142,398.72 : 196,495.20 = 78,726.24 : x
2. Step 2: Convert to fraction form
   142,398.72/196,495.20 = 78,726.24/x
3. Step 3: Cross multiply
   142,398.72x = 196,495.20 × 78,726.24
4. Step 4: Simplify right side
   142,398.72x = 15,469,328,274.05
5. Step 5: Solve for x
   x = 15,469,328,274.05/142,398.72
6. Step 6: Final answer
   x = 108,633.90