Finding the Fourth Proportional to 142,109.78, 196,111.76 and 78,447.65

Step by Step Solution

1. Step 1: Write the proportion equation
   142,109.78 : 196,111.76 = 78,447.65 : x
2. Step 2: Convert to fraction form
   142,109.78/196,111.76 = 78,447.65/x
3. Step 3: Cross multiply
   142,109.78x = 196,111.76 × 78,447.65
4. Step 4: Simplify right side
   142,109.78x = 15,384,505,336.57
5. Step 5: Solve for x
   x = 15,384,505,336.57/142,109.78
6. Step 6: Final answer
   x = 108,257.90