Finding the Fourth Proportional to 103,680.10, 155,684.18 and 78,748.30

Step by Step Solution

1. Step 1: Write the proportion equation
   103,680.10 : 155,684.18 = 78,748.30 : x
2. Step 2: Convert to fraction form
   103,680.10/155,684.18 = 78,748.30/x
3. Step 3: Cross multiply
   103,680.10x = 155,684.18 × 78,748.30
4. Step 4: Simplify right side
   103,680.10x = 12,259,864,511.89
5. Step 5: Solve for x
   x = 12,259,864,511.89/103,680.10
6. Step 6: Final answer
   x = 118,247.04