Finding the Fourth Proportional to 76,399.76, 105,431.30 and 42,408.66

Step by Step Solution

1. Step 1: Write the proportion equation
   76,399.76 : 105,431.30 = 42,408.66 : x
2. Step 2: Convert to fraction form
   76,399.76/105,431.30 = 42,408.66/x
3. Step 3: Cross multiply
   76,399.76x = 105,431.30 × 42,408.66
4. Step 4: Simplify right side
   76,399.76x = 4,471,200,155.06
5. Step 5: Solve for x
   x = 4,471,200,155.06/76,399.76
6. Step 6: Final answer
   x = 58,523.75