Finding the Fourth Proportional to 142,638, 196,839.69 and 78,106.07

Step by Step Solution

1. Step 1: Write the proportion equation
   142,638 : 196,839.69 = 78,106.07 : x
2. Step 2: Convert to fraction form
   142,638/196,839.69 = 78,106.07/x
3. Step 3: Cross multiply
   142,638x = 196,839.69 × 78,106.07
4. Step 4: Simplify right side
   142,638x = 15,374,373,621.72
5. Step 5: Solve for x
   x = 15,374,373,621.72/142,638
6. Step 6: Final answer
   x = 107,785.96