Finding the Fourth Proportional to 103,698.35, 155,711.55 and 78,766.55

Step by Step Solution

1. Step 1: Write the proportion equation
   103,698.35 : 155,711.55 = 78,766.55 : x
2. Step 2: Convert to fraction form
   103,698.35/155,711.55 = 78,766.55/x
3. Step 3: Cross multiply
   103,698.35x = 155,711.55 × 78,766.55
4. Step 4: Simplify right side
   103,698.35x = 12,264,861,588.65
5. Step 5: Solve for x
   x = 12,264,861,588.65/103,698.35
6. Step 6: Final answer
   x = 118,274.41