Finding the Fourth Proportional to 76,478.55, 105,540.30 and 42,490.17

Step by Step Solution

1. Step 1: Write the proportion equation
   76,478.55 : 105,540.30 = 42,490.17 : x
2. Step 2: Convert to fraction form
   76,478.55/105,540.30 = 42,490.17/x
3. Step 3: Cross multiply
   76,478.55x = 105,540.30 × 42,490.17
4. Step 4: Simplify right side
   76,478.55x = 4,484,425,288.85
5. Step 5: Solve for x
   x = 4,484,425,288.85/76,478.55
6. Step 6: Final answer
   x = 58,636.38