Finding the Fourth Proportional to 76,389.60, 105,414.76 and 42,399.60

Step by Step Solution

1. Step 1: Write the proportion equation
   76,389.60 : 105,414.76 = 42,399.60 : x
2. Step 2: Convert to fraction form
   76,389.60/105,414.76 = 42,399.60/x
3. Step 3: Cross multiply
   76,389.60x = 105,414.76 × 42,399.60
4. Step 4: Simplify right side
   76,389.60x = 4,469,543,658.10
5. Step 5: Solve for x
   x = 4,469,543,658.10/76,389.60
6. Step 6: Final answer
   x = 58,509.85