Finding the Fourth Proportional to 142,139.88, 196,152.91 and 78,478.07

Step by Step Solution

1. Step 1: Write the proportion equation
   142,139.88 : 196,152.91 = 78,478.07 : x
2. Step 2: Convert to fraction form
   142,139.88/196,152.91 = 78,478.07/x
3. Step 3: Cross multiply
   142,139.88x = 196,152.91 × 78,478.07
4. Step 4: Simplify right side
   142,139.88x = 15,393,700,624.72
5. Step 5: Solve for x
   x = 15,393,700,624.72/142,139.88
6. Step 6: Final answer
   x = 108,299.66