Finding the Fourth Proportional to 129,978.10, 194,639.10 and 85,363.30

Step by Step Solution

1. Step 1: Write the proportion equation
   129,978.10 : 194,639.10 = 85,363.30 : x
2. Step 2: Convert to fraction form
   129,978.10/194,639.10 = 85,363.30/x
3. Step 3: Cross multiply
   129,978.10x = 194,639.10 × 85,363.30
4. Step 4: Simplify right side
   129,978.10x = 16,615,035,885.03
5. Step 5: Solve for x
   x = 16,615,035,885.03/129,978.10
6. Step 6: Final answer
   x = 127,829.50