Finding the Fourth Proportional to 103,689.10, 155,697.68 and 78,757.30

Step by Step Solution

1. Step 1: Write the proportion equation
   103,689.10 : 155,697.68 = 78,757.30 : x
2. Step 2: Convert to fraction form
   103,689.10/155,697.68 = 78,757.30/x
3. Step 3: Cross multiply
   103,689.10x = 155,697.68 × 78,757.30
4. Step 4: Simplify right side
   103,689.10x = 12,262,328,893.06
5. Step 5: Solve for x
   x = 12,262,328,893.06/103,689.10
6. Step 6: Final answer
   x = 118,260.54