Finding the Fourth Proportional to 76,404.50, 105,439.83 and 42,870.50

Step by Step Solution

1. Step 1: Write the proportion equation
   76,404.50 : 105,439.83 = 42,870.50 : x
2. Step 2: Convert to fraction form
   76,404.50/105,439.83 = 42,870.50/x
3. Step 3: Cross multiply
   76,404.50x = 105,439.83 × 42,870.50
4. Step 4: Simplify right side
   76,404.50x = 4,520,258,232.02
5. Step 5: Solve for x
   x = 4,520,258,232.02/76,404.50
6. Step 6: Final answer
   x = 59,162.20